Income Taxes - Components of Income Tax Expense (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Federal
Current	$ 717	$ 556	$ 1,631	$ 1,355
Deferred	(232)	(114)	(279)	(81)
Federal income tax	485	442	1,352	1,274
State
Current	108	103	235	283
Deferred	(27)	(11)	25	(16)
State income tax	81	92	260	267
Applicable income taxes	$ 566	$ 534	$ 1,612	$ 1,541

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

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