Investments (Net Realized Gains) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Income tax effect (included in Provision for Income Taxes on the Condensed Consolidated Statements of Operations)	$ (3,242)	$ (3,096)	$ (2,817)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Schedule of Available-for-sale Securities [Line Items]
Total OTTI	(8)	(6)	(12)
Portion of loss recognized in other comprehensive income	0	0	0
Net OTTI recognized in earnings	(8)	(6)	(12)
Gross realized losses from sales	(9)	(13)	(11)
Gross realized gains from sales	198	175	136
Net realized gains (included in Investment and Other Income on the Condensed Consolidated Statements of Operations)	181	156	113
Income tax effect (included in Provision for Income Taxes on the Condensed Consolidated Statements of Operations)	(66)	(57)	(41)
Realized gains, net of taxes	$ 115	$ 99	$ 72