Fair Value of Derivative Instruments (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	$ 18	$ 6
Fair Value, Liability Derivatives	13	16
Interest Rate Caps [Member]
Schedule of Cost-method Investments [Line Items]
Derivative, Notional Amount	10,179	0
Currency Swap [Member]
Schedule of Cost-method Investments [Line Items]
Derivative, Notional Amount	811	0
Interest Rate Swap [Member]
Schedule of Cost-method Investments [Line Items]
Derivative, Notional Amount	900	0
Designated as Hedging Instrument | Interest Rate Swap [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	1	1
Fair Value, Liability Derivatives	5	3
Not Designated as Hedging Instrument | Currency Swap [Member]
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	16	5
Fair Value, Liability Derivatives	2	2
Not Designated as Hedging Instrument | Interest Rate Contract
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	1	0
Fair Value, Liability Derivatives	5	10
Not Designated as Hedging Instrument | Commodity Contract
Schedule of Cost-method Investments [Line Items]
Fair Value, Asset Derivatives	0	0
Fair Value, Liability Derivatives	1	1
Interest Rate Caps Sold | Interest Rate Caps [Member]
Schedule of Cost-method Investments [Line Items]
Derivative, Notional Amount	$ 8,200	$ 6,200