Equity (Components of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31,	$ 10,580	$ 11,397
OCI before reclassifications	(4,309)	(5,120)
Amounts reclassified from AOCI	(69)	(75)
Balance at June 30,	6,202	6,202
Unrealized Investment Gains (Losses), Net of Related Offsets [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31,	13,332	13,590
OCI before reclassifications	(3,476)	(3,575)
Amounts reclassified from AOCI	(147)	(306)
Balance at June 30,	9,709	9,709
Unrealized Gains (Losses) on Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31,	905	829
OCI before reclassifications	(215)	(255)
Amounts reclassified from AOCI	44	160
Balance at June 30,	734	734
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31,	(1,205)	(533)
OCI before reclassifications	(620)	(1,292)
Amounts reclassified from AOCI	0	0
Balance at June 30,	(1,825)	(1,825)
Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at December 31,	(2,452)	(2,489)
OCI before reclassifications	2	2
Amounts reclassified from AOCI	34	71
Balance at June 30,	$ (2,416)	$ (2,416)