Change in Net Unrealized Gains (Losses) on Available-for-Sale Securities Reported in Accumulated Other Comprehensive Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Investments [Abstract]
Net unrealized investment gains (losses), beginning of period	$ 926	[1]	$ 2,638	[1]	$ 1,485	[1]
Unrealized gains (losses) on investment securities	3,244		(3,780)		2,318
Adjustment to DAC	(172)		248		(159)
Adjustment to PVFP	(66)		95		(6)
Adjustment to sales inducements	(15)		40		(33)
Adjustment to benefit reserves	(534)		673		(424)
Provision for income taxes	(862)		952		(590)
Change in unrealized gains (losses) on investment securities	1,595	[1]	(1,772)	[1]	1,106	[1]
Reclassification adjustments to net investment (gains) losses, net of taxes	(12)	[1]	21	[1]	50	[1]
Change in net unrealized investment gains (losses)	1,583	[1]	(1,751)	[1]	1,156	[1]
Less: change in net unrealized investment gains (losses) attributable to noncontrolling interests	56	[1]	(39)	[1]	3	[1]
Net unrealized investment gains (losses), end of period	$ 2,453	[1]	$ 926	[1]	$ 2,638	[1]

[1] Net of adjustments to DAC, PVFP, sales inducements and benefit reserves. See note 4 for additional information.