Accounting Changes - Leases, Tax Reform, Net Benefit Cost (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | |||||
|---|---|---|---|---|---|---|---|
Jan. 01, 2018 |
Mar. 31, 2018 |
Mar. 31, 2017 |
Dec. 31, 2017 |
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| Accounting Changes | |||||||
| Operating lease commitments | $ 6,600 | ||||||
| Sales-type lease revenue recognized based on use of residual value guarantee insurance | $ 452 | ||||||
| Reclassification from AOCI to retained earnings for stranded tax effects of U.S. tax reform | $ (2,420) | ||||||
| Cost of sales | $ 10,825 | $ 10,211 | [1] | ||||
| Selling, general and administrative | 5,445 | 5,027 | [1] | ||||
| Research, development and engineering | $ 1,405 | 1,484 | [1] | ||||
| Accounting Standards Update 2017-07, Improving the Presentation of Net Benefit Cost | Adjustments for adoption of guidance | Other (Income) and Expense | |||||||
| Accounting Changes | |||||||
| Cost of sales | (172) | ||||||
| Selling, general and administrative | (125) | ||||||
| Research, development and engineering | $ (49) | ||||||
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