Derivative Instruments and Hedging Activity - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Maximum length of time hedge in cash flow hedge	12 months
Terminated interest rate contract	$ 765,000,000	$ 1,650,000,000
Gain on termination of interest rate contract	34,000,000	33,000,000
Terminated fair value hedges			$ 0
Gain (loss) on hedged item in fair value hedge	(9,000,000)	43,000,000	(68,000,000)
Deferred, net after-tax gains on derivative instruments	3,000,000
Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative notional amount	0	0	$ 0
Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative notional amount	822,000,000	580,000,000
Foreign exchange contract
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative notional amount	561,000,000	378,000,000
Interest rate contract
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative notional amount	0	0
Interest rate contract | Fair value hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative notional amount	$ 200,000,000	$ 1,300,000,000