Derivative Financial Instruments - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	May 08, 2018
Derivative [Line Items]
Net gain (loss) on derivative financial instruments	$ (12,000,000)	$ (12,000,000)	$ (12,000,000)	$ (40,000,000)
Recognized unrealized losses in AOCI reclassified to interest expense	316,000,000	316,000,000
Reclassification out of AOCI [Member]
Derivative [Line Items]
Recognized unrealized losses in AOCI reclassified to interest expense		67,000,000	67,000,000
Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Notional value of outstanding derivative contracts					$ 1,940,000,000
Fair value of swap arrangement in net liability position	67,000,000	67,000,000	67,000,000
Term Facility [Member] | Interest Rate Swap [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Notional value of outstanding derivative contracts					$ 1,940,000,000
Foreign Exchange Rate [Member]
Derivative [Line Items]
Notional value of outstanding derivative contracts	664,000,000	664,000,000	$ 664,000,000
Derivative contracts, maturity date			Sep. 30, 2023
Fair value of derivative contracts	9,000,000	9,000,000	$ 9,000,000
Net gain (loss) on derivative financial instruments	(12,000,000)	(12,000,000)	(12,000,000)
Net deferred losses expected to be reclassified from AOCI over next 12 months	$ (6,000,000)	$ (6,000,000)	$ (6,000,000)