Variable Interest Entities Reflects adoption of ASU 2015-12 - Schedule of Net Gain (Loss) Related to Consolidated VIEs (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2019 |
Jun. 30, 2018 |
|
| Variable Interest Entity [Line Items] | ||||
| Nonoperating net gain (loss) on consolidated VIEs | $ 89 | $ 3 | $ 231 | $ 18 |
| Net income (loss) attributable to noncontrolling interests | 10 | 5 | 17 | 10 |
| Consolidated Variable Interest Entities [Member] | ||||
| Variable Interest Entity [Line Items] | ||||
| Nonoperating net gain (loss) on consolidated VIEs | 39 | (14) | 133 | (12) |
| Net income (loss) attributable to noncontrolling interests | $ 12 | $ 6 | $ 17 | $ 11 |