v3.10.0.1
Pension and Postretirement Benefit Plans and Defined Contribution Plans - Plan Assets (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Postretirement Benefits Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [2] $ 469 [1] $ 494 [1] $ 458
Assets Measured at NAV [1],[3]   0  
Postretirement Benefits Plan [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 0  
Postretirement Benefits Plan [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 469 494  
Postretirement Benefits Plan [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 0  
Postretirement Benefits Plan [Member] | Cash and Cash Equivalents [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1] 0 0  
Postretirement Benefits Plan [Member] | Cash and Cash Equivalents [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 0  
Postretirement Benefits Plan [Member] | Cash and Cash Equivalents [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4]   0  
Postretirement Benefits Plan [Member] | Equity Securities [Member] | Global Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1] 0 0  
Postretirement Benefits Plan [Member] | Equity Securities [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1] 0 0  
Assets Measured at NAV [1],[3]   0  
Postretirement Benefits Plan [Member] | Equity Securities [Member] | Level 1 [Member] | Global Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 0  
Postretirement Benefits Plan [Member] | Equity Securities [Member] | Level 1 [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4]   0  
Postretirement Benefits Plan [Member] | Equity Securities [Member] | Level 2 [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 0  
Postretirement Benefits Plan [Member] | Equity Securities [Member] | Level 3 [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 0  
Postretirement Benefits Plan [Member] | Corporate debt [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1] 0 0  
Postretirement Benefits Plan [Member] | Corporate debt [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4]   0  
Postretirement Benefits Plan [Member] | Corporate debt [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 0  
Postretirement Benefits Plan [Member] | Corporate debt [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4]   0  
Postretirement Benefits Plan [Member] | Government and Agency Obligations [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1] 0 0  
Postretirement Benefits Plan [Member] | Government and Agency Obligations [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 0  
Postretirement Benefits Plan [Member] | Government and Agency Obligations [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 0  
Postretirement Benefits Plan [Member] | Government and Agency Obligations [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0    
Postretirement Benefits Plan [Member] | Fixed Income Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1] 0 0  
Assets Measured at NAV [1],[3]   0  
Postretirement Benefits Plan [Member] | Fixed Income Commingled Funds [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4]   0  
Postretirement Benefits Plan [Member] | Fixed Income Commingled Funds [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 0  
Postretirement Benefits Plan [Member] | Fixed Income Commingled Funds [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 0  
Postretirement Benefits Plan [Member] | Partnership Interest [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[5] 0 0  
Assets Measured at NAV [1],[3],[5]   0  
Postretirement Benefits Plan [Member] | Partnership Interest [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4],[5] 0 0  
Postretirement Benefits Plan [Member] | Partnership Interest [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4],[5] 0 0  
Postretirement Benefits Plan [Member] | Insurance Contracts [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1] 469 494  
Postretirement Benefits Plan [Member] | Insurance Contracts [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0    
Postretirement Benefits Plan [Member] | Insurance Contracts [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 469 494  
Postretirement Benefits Plan [Member] | Insurance Contracts [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4]   0  
Postretirement Benefits Plan [Member] | Other Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1] 0 [6] 0 [7]  
Assets Measured at NAV [1],[3],[7]   0  
Postretirement Benefits Plan [Member] | Other Commingled Funds [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 [6] 0 [7]  
Postretirement Benefits Plan [Member] | Other Commingled Funds [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 [6] 0 [7]  
Postretirement Benefits Plan [Member] | Other Commingled Funds [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [1],[4] 0 [6] 0 [7]  
United States [Member] | Pension Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [8] 13,051 14,284 12,556
Assets Measured at NAV [3] 2,581 2,889  
United States [Member] | Pension Plan [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 3,173 4,238  
United States [Member] | Pension Plan [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 7,294 7,153  
United States [Member] | Pension Plan [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 3 4  
United States [Member] | Pension Plan [Member] | Cash and Cash Equivalents [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 443 655  
United States [Member] | Pension Plan [Member] | Cash and Cash Equivalents [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 53 115  
United States [Member] | Pension Plan [Member] | Cash and Cash Equivalents [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 390 540  
United States [Member] | Pension Plan [Member] | Cash and Cash Equivalents [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
United States [Member] | Pension Plan [Member] | Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 177 253  
United States [Member] | Pension Plan [Member] | Equity Securities [Member] | Global Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 3,156 4,157  
United States [Member] | Pension Plan [Member] | Equity Securities [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 933 1,194  
Assets Measured at NAV [3] 299 392  
United States [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 1 [Member] | Global Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 3,119 4,118  
United States [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 1 [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
United States [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 2 [Member] | Global Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 37 38  
United States [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 2 [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 634 802  
United States [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 3 [Member] | Global Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 1  
United States [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 3 [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
United States [Member] | Pension Plan [Member] | Corporate debt [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 4,654 4,250  
United States [Member] | Pension Plan [Member] | Corporate debt [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 1 5  
United States [Member] | Pension Plan [Member] | Corporate debt [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 4,650 4,242  
United States [Member] | Pension Plan [Member] | Corporate debt [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 3 3  
United States [Member] | Pension Plan [Member] | Government and Agency Obligations [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 1,391 1,316  
United States [Member] | Pension Plan [Member] | Government and Agency Obligations [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
United States [Member] | Pension Plan [Member] | Government and Agency Obligations [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 1,391 1,316  
United States [Member] | Pension Plan [Member] | Government and Agency Obligations [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
United States [Member] | Pension Plan [Member] | Fixed Income Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 96 94  
Assets Measured at NAV [3] 96 94  
United States [Member] | Pension Plan [Member] | Fixed Income Commingled Funds [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4]   0  
United States [Member] | Pension Plan [Member] | Fixed Income Commingled Funds [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
United States [Member] | Pension Plan [Member] | Fixed Income Commingled Funds [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
United States [Member] | Pension Plan [Member] | Partnership Interest [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [5] 1,165 1,197  
Assets Measured at NAV [3],[5] 1,165 1,197  
United States [Member] | Pension Plan [Member] | Partnership Interest [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[5] 0 0  
United States [Member] | Pension Plan [Member] | Partnership Interest [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[5]   0  
United States [Member] | Pension Plan [Member] | Partnership Interest [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[5] 0 0  
United States [Member] | Pension Plan [Member] | Insurance Contracts [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 192 215  
United States [Member] | Pension Plan [Member] | Insurance Contracts [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
United States [Member] | Pension Plan [Member] | Insurance Contracts [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 192 215  
United States [Member] | Pension Plan [Member] | Insurance Contracts [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
United States [Member] | Pension Plan [Member] | Other Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [7] 1,021 1,206  
Assets Measured at NAV [3],[7] 1,021 1,206  
United States [Member] | Pension Plan [Member] | Other Commingled Funds [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[7] 0 0  
United States [Member] | Pension Plan [Member] | Other Commingled Funds [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[7] 0 0  
Foreign Plan [Member] | Pension Plan [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [9] 8,215 8,863 7,683
Assets Measured at NAV [3] 2,300 2,709  
Foreign Plan [Member] | Pension Plan [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 40 194  
Foreign Plan [Member] | Pension Plan [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 4,809 5,073  
Foreign Plan [Member] | Pension Plan [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 1,065 887  
Foreign Plan [Member] | Pension Plan [Member] | Cash and Cash Equivalents [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 246 385  
Foreign Plan [Member] | Pension Plan [Member] | Cash and Cash Equivalents [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 39 48  
Foreign Plan [Member] | Pension Plan [Member] | Cash and Cash Equivalents [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 208 337  
Foreign Plan [Member] | Pension Plan [Member] | Cash and Cash Equivalents [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Equity Securities [Member] | Global Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 2 154  
Foreign Plan [Member] | Pension Plan [Member] | Equity Securities [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 1,876 2,897  
Assets Measured at NAV [3] 463 1,303  
Foreign Plan [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 1 [Member] | Global Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 2 146  
Foreign Plan [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 1 [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 2 [Member] | Global Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 8  
Foreign Plan [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 2 [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 1,413 1,594  
Foreign Plan [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 3 [Member] | Global Equity Securities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Equity Securities [Member] | Level 3 [Member] | Equity Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Corporate debt [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 727 588  
Assets Measured at NAV [3] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Corporate debt [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Corporate debt [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 727 588  
Foreign Plan [Member] | Pension Plan [Member] | Corporate debt [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Government and Agency Obligations [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [10] 1,305 716  
Assets Measured at NAV [3],[10] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Government and Agency Obligations [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[10] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Government and Agency Obligations [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[10] 1,305 716  
Foreign Plan [Member] | Pension Plan [Member] | Government and Agency Obligations [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[10] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Fixed Income Commingled Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 1,770 2,181  
Assets Measured at NAV [3] 762 841  
Foreign Plan [Member] | Pension Plan [Member] | Fixed Income Commingled Funds [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Fixed Income Commingled Funds [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 1,007 1,340  
Foreign Plan [Member] | Pension Plan [Member] | Fixed Income Commingled Funds [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Partnership Interest [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [5] 57 42  
Assets Measured at NAV [3],[5] 53 35  
Foreign Plan [Member] | Pension Plan [Member] | Partnership Interest [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[5] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Partnership Interest [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[5] 4 7  
Foreign Plan [Member] | Pension Plan [Member] | Partnership Interest [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[5] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Insurance Contracts [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [11] 759 496  
Assets Measured at NAV [3],[11] 1 1  
Foreign Plan [Member] | Pension Plan [Member] | Insurance Contracts [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[11] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Insurance Contracts [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[11] 74 75  
Foreign Plan [Member] | Pension Plan [Member] | Insurance Contracts [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets 684 [4],[11] 420 [4],[11] 254
Foreign Plan [Member] | Pension Plan [Member] | Other [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [7],[11] 1,473 1,404  
Assets Measured at NAV [3],[7],[11] 1,020 528  
Foreign Plan [Member] | Pension Plan [Member] | Other [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[7],[11] 0 0  
Foreign Plan [Member] | Pension Plan [Member] | Other [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets [4],[7],[11] 71 408  
Foreign Plan [Member] | Pension Plan [Member] | Other [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of plan assets $ 382 [4],[7],[11] $ 468 [4],[7],[11] $ 324
[1] Reflects postretirement plan assets, which support a portion of our U.S. retiree medical plans.
[2] The favorable change in the funded status of our postretirement plans was primarily due to an increase in the discount rate at the end of 2018, partially offset by a decrease in actual return on plan assets.
[3] Certain investments that are measured at NAV per share (or its equivalent) have not been classified in the fair value hierarchy. The NAV amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented for the total pension benefits plan assets.
[4] Fair values are determined based on valuation inputs categorized as Level 1, 2 or 3 (see Note 1E).
[5] Primarily includes investments in private equity, private debt, public equity limited partnerships, and, to a lesser extent, real estate and venture capital.
[6] Represents net reimbursements to our partners for selling, informational and administrative expenses incurred.
[7] Primarily includes, for U.S. plan assets, investments in hedge funds and, to a lesser extent, real estate and, for international plan assets, investments in real estate and hedge funds.
[8] The favorable change in the funded status of our U.S. qualified plans was primarily due to an increase in the discount rate at the end of 2018, partially offset by a decrease in actual return on plan assets.
[9] The favorable change in the international plans’ funded status was primarily due to favorable currency movements, partially offset by a decrease in the actual return on plan assets.
[10] Government and agency obligations are inclusive of repurchase agreements.
[11] See below for a tabular analysis of the changes in Level 3 investments valued using significant unobservable inputs.