Leases - Maturities of Operating Lease Liabilities (Detail) $ in Millions	Mar. 31, 2019 USD ($)
Operating Lease Liabilities Payments Due [Abstract]
2019 (excluding the three months ended March 31, 2019)	$ 32
2020	33
2021	22
2022	17
2023	15
Thereafter	45
Total operating lease payments	164
Less imputed interest	(16)
Total operating lease liabilities	$ 148