Revenue - Schedule of Changes in Technology Services Deferred Revenue Liability (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2019 |
Jun. 30, 2018 |
|
| Revenue From Contract With Customer [Abstract] | ||||
| Beginning balance | $ 73 | $ 66 | $ 70 | $ 62 |
| Acquisition, net of revenue recognized | 24 | 24 | ||
| Additions | 12 | 8 | 23 | 20 |
| Revenue recognized that was included in the beginning balance | (9) | (10) | (17) | (18) |
| Ending balance | $ 100 | $ 64 | $ 100 | $ 64 |