v3.10.0.1
Tax Matters - Reconciliation of Gross Unrecognized Tax Benefits (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]      
Balance, beginning $ (6,558) [1] $ (5,826) [1] $ (5,919)
Acquisitions [2] 0 10 (83)
Increases based on tax positions taken during a prior period [3] (192) (49) (11)
Decreases based on tax positions taken during a prior period [3],[4] 561 28 409
Decreases based on settlements for a prior period [5] 123 35 126
Increases based on tax positions taken during the current period [3] (370) (753) (489)
Impact of foreign exchange 56 (121) (5)
Other, net [3],[6] 121 118 146
Balance, ending [1] $ (6,259) $ (6,558) $ (5,826)
[1] In 2018, included in Income taxes payable ($11 million), Current tax assets ($1 million), Noncurrent deferred tax assets and other noncurrent tax assets ($47 million), Noncurrent deferred tax liabilities ($3.2 billion) and Other taxes payable ($3.0 billion). In 2017, included in Income taxes payable ($1 million), Noncurrent deferred tax assets and other noncurrent tax assets ($123 million), Noncurrent deferred tax liabilities ($3.3 billion) and Other taxes payable ($3.2 billion).
[2] For 2017 and 2016, primarily related to the acquisitions of Medivation and Anacor. See also Note 2A.
[3] Primarily included in Provision/(benefit) for taxes on income.
[4] Primarily related to effectively settling certain tax positions primarily with foreign tax authorities. See also Note 5A.
[5] Primarily related to cash payments and reductions of tax attributes.
[6] Primarily related to decreases as a result of a lapse of applicable statutes of limitations.