Component of Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balances, beginning		$ 14,467	$ 14,637	$ 16,797
OCI before reclassifications		205	228	(1,698)
Amounts reclassified from (to) OCI		(160)	(137)	(70)
Total other comprehensive income (loss)		45	91	(1,768)
Balances before nonnontrolling interests		3,139	3,101	2,678
Less: change in OCI attributable to noncontrolling interests		112	7	(332)
Balances, ending		15,328	14,467	14,637
Net unrealized investment (gains) losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balances, beginning	[1]	1,262	1,254	2,453
OCI before reclassifications	[1]	(84)	54	(1,218)
Amounts reclassified from (to) OCI	[1]	(102)	(57)	5
Total other comprehensive income (loss)	[1]	(186)	(3)	(1,213)
Balances before nonnontrolling interests	[1]	1,076	1,251	1,240
Less: change in OCI attributable to noncontrolling interests	[1]	(9)	(11)	(14)
Balances, ending	[1]	1,085	1,262	1,254
Derivatives qualifying as hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balances, beginning	[2]	2,085	2,045	2,070
OCI before reclassifications	[2]	38	120	50
Amounts reclassified from (to) OCI	[2]	(58)	(80)	(75)
Total other comprehensive income (loss)	[2]	(20)	40	(25)
Balances before nonnontrolling interests	[2]	2,065	2,085	2,045
Less: change in OCI attributable to noncontrolling interests	[2]	0	0	0
Balances, ending	[2]	2,065	2,085	2,045
Foreign currency translation and other adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balances, beginning		(253)	(289)	(77)
OCI before reclassifications		251	54	(530)
Amounts reclassified from (to) OCI		0	0	0
Total other comprehensive income (loss)		251	54	(530)
Balances before nonnontrolling interests		(2)	(235)	(607)
Less: change in OCI attributable to noncontrolling interests		121	18	(318)
Balances, ending		(123)	(253)	(289)
Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balances, beginning		3,094	3,010	4,446
Total other comprehensive income (loss)		(67)	84	(1,460)
Balances, ending		$ 3,027	$ 3,094	$ 3,010

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

[2] See note 5 for additional information.