Derivative Financial Instruments - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Derivative [Line Items]
Notional values of derivative contracts	$ 419		$ 419		$ 1,765
Decrease in debt carrying value due to fair value hedge	14		14		15
Losses on current derivative instruments designated as cash flow hedges are reported in OCI net of tax (less than $1 million at June 30, 2017 and December 31, 2016)	1		1		1
Unrealized net losses on cash flow hedges (less than $1 million)			1
HSBC Bank USA [Member]
Derivative [Line Items]
Notional values of derivative contracts	419		419		1,800
Fair value of collateral agreements with affiliate counterparties	35		35		$ 317
Derivative related income (expense) [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 0	$ 0	$ 0	$ (117)