Equity (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	$ 14,632	$ 6,443	$ 4,771	$ 10,649
OCI before reclassifications	(1,300)	728	12,905	(5,269)
Deferred income tax benefit (expense)	404	(411)	(3,835)	1,345
AOCI before reclassifications, net of income tax	13,736	6,760	13,841	6,725
Amounts reclassified from AOCI	(221)	194	(368)	269
Deferred income tax benefit (expense)	80	(63)	122	(103)
Amounts reclassified from AOCI, net of income tax	(141)	131	(246)	166
Balance, end of period	13,595	6,891	13,595	6,891
Unrealized Investment Gains (Losses), Net of Related Offsets
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	18,204	11,761	10,315	15,159
OCI before reclassifications	(1,066)	962	10,872	(3,923)
Deferred income tax benefit (expense)	281	(340)	(3,656)	1,337
AOCI before reclassifications, net of income tax	17,419	12,383	17,531	12,573
Amounts reclassified from AOCI	(173)	(102)	(339)	(392)
Deferred income tax benefit (expense)	60	34	114	134
Amounts reclassified from AOCI, net of income tax	(113)	(68)	(225)	(258)
Balance, end of period	17,306	12,315	17,306	12,315
Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	2,431	1,102	1,458	1,076
OCI before reclassifications	(24)	102	1,472	(106)
Deferred income tax benefit (expense)	8	(47)	(460)	37
AOCI before reclassifications, net of income tax	2,415	1,157	2,470	1,007
Amounts reclassified from AOCI	(94)	239	(174)	490
Deferred income tax benefit (expense)	30	(77)	55	(178)
Amounts reclassified from AOCI, net of income tax	(64)	162	(119)	312
Balance, end of period	2,351	1,319	2,351	1,319
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(4,020)	(4,214)	(4,950)	(3,303)
OCI before reclassifications	49	(336)	809	(1,243)
Deferred income tax benefit (expense)	30	(24)	200	(28)
AOCI before reclassifications, net of income tax	(3,941)	(4,574)	(3,941)	(4,574)
Amounts reclassified from AOCI	0	0	0	0
Deferred income tax benefit (expense)	0	0	0	0
Amounts reclassified from AOCI, net of income tax	0	0	0	0
Balance, end of period	(3,941)	(4,574)	(3,941)	(4,574)
Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(1,983)	(2,206)	(2,052)	(2,283)
OCI before reclassifications	(259)	0	(248)	3
Deferred income tax benefit (expense)	85	0	81	(1)
AOCI before reclassifications, net of income tax	(2,157)	(2,206)	(2,219)	(2,281)
Amounts reclassified from AOCI	46	57	145	171
Deferred income tax benefit (expense)	(10)	(20)	(47)	(59)
Amounts reclassified from AOCI, net of income tax	36	37	98	112
Balance, end of period	$ (2,121)	$ (2,169)	$ (2,121)	$ (2,169)