Restructuring Charges - Components of Restructuring Charges Less Releases Recorded in Liabilities (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Restructuring Cost and Reserve [Line Items] | |||
| Net restructuring charges | $ 6 | $ 1 | $ 68 |
| Personnel Lay-Off Costs [Member] | |||
| Restructuring Cost and Reserve [Line Items] | |||
| Net restructuring charges | 4 | 7 | 52 |
| Other Exit Costs [Member] | |||
| Restructuring Cost and Reserve [Line Items] | |||
| Net restructuring charges | 2 | 10 | 19 |
| Release of Provisions/Accruals [Member] | |||
| Restructuring Cost and Reserve [Line Items] | |||
| Net restructuring charges | $ 0 | $ (16) | $ (3) |