Leases - Maturities (Detail) $ in Millions	Sep. 30, 2019 USD ($)
Operating
2019 (excluding nine months ended September 30, 2019)	$ 22
2020	65
2021	59
2022	59
2023	51
Thereafter	416
Total lease payments	672
Less: interest	(194)
Discounted lease liabilities	478
Financing
2019 (excluding six months ended June 30, 2019)	12
2020	42
2021	40
2022	39
2023	38
Thereafter	273
Total lease payments	444
Less: interest	(118)
Discounted lease liabilities	$ 326