Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current income tax:
Federal									$ 549	$ 229	$ 250
State and local									24	25	21
Foreign									37	31	23
Total current income tax									610	285	294
Deferred income tax:
Federal									(102)	37	90
State and local									(10)	15	1
Foreign									(6)	(2)	(8)
Total deferred income tax									(118)	50	83
Total income tax provision (benefit)									492	335	377
Geographic sources of pretax income (loss)
United States									1,640	1,161	1,350
Foreign									330	77	97
Income from continuing operations before income tax provision	479	602	402	487	418	199	299	322	1,970	1,238	1,447
Reconciliation of the income tax provision
Tax at U.S. statutory rate (as a percent)									35.00%	35.00%	35.00%
Changes in taxes resulting from:
Dividend exclusion (as a percent)									(5.10%)	(5.90%)	(8.50%)
Low income housing credits (as a percent)									(2.70%)	(3.00%)	(1.10%)
Net income (loss) attributable to noncontrolling interest (as a percent)									(2.50%)	3.60%	2.60%
Foreign tax credits, net of addback (as a percent)									(0.90%)	(3.20%)	(2.20%)
Tax-exempt interest income (as a percent)									(0.90%)	(1.70%)	(1.30%)
State taxes, net of federal benefit (as a percent)									0.50%	2.50%	1.00%
Taxes applicable to prior years (as a percent)									0.00%	(2.50%)	0.20%
Other, net (as a percent)									1.60%	2.30%	0.40%
Income tax provision (as a percent)									25.00%	27.10%	26.10%
Accumulated earnings of foreign subsidiaries									120
Aggregate U.S. federal taxes not provided on earnings of foreign subsidiaries									$ 17