Deferred Gains - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Liabilities Disclosure [Abstract]
Deferred gains on sale of assets included in accrued expenses and other liabilities	$ 1,412	$ 1,168
Amortization of deferred gains	$ 91	$ 86	$ 91