Leases - Maturities (Detail) $ in Millions	Mar. 31, 2019 USD ($)
Operating
2019 (excluding three months ended March 31, 2019)	$ 67
2020	82
2021	59
2022	46
2023	42
Thereafter	414
Total lease payments	710
Operating leases not yet commenced	167
Financing
2019 (excluding three months ended March 31, 2019)	28
2020	34
2021	31
2022	31
2023	29
Thereafter	188
Total lease payments	341
Finance leases not yet commenced	$ 61