Quarterly Results (Unaudited) Level 4 (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock															21.2		0	6.2	0
Revenues	$ 4,617		$ 4,769		$ 4,616		$ 4,612		$ 4,777		$ 4,862		$ 4,734		$ 6,300		$ 18,614	$ 20,673	$ 22,086
Benefits, Losses and Expenses	4,173		4,273		4,466		4,003		4,295		4,416		4,497		5,994		16,915	19,202	22,175
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	345		388		150		466		384		365		233		243		1,349	1,225	220
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	37		0		(617)		29		(70)		(72)		(423)		(484)		(551)	(1,049)	(258)
Net Income (Loss) Attributable to Parent	382		388		(467)		495		314		293		(190)		(241)		798	176	(38)
Preferred Stock Dividends and Other Adjustments	0		0		0		0		0		0		0		10
Net Income (Loss) Available to Common Stockholders, Basic	382		388		(467)		495		314		293		(190)		(251)		798	166	(80)
Earnings Per Share, Basic	$ 890,000.00		$ 890,000.00		$ (1,040,000.00)		$ 1,100,000.00		$ 700,000.00		$ 650,000.00		$ (420,000.00)		$ (580,000.00)		$ 1.81	$ 0.37	$ (0.18)
Earnings Per Share, Diluted	$ 860,000.00		$ 860,000.00		$ (1,000,000.00)		$ 1,030,000.00		$ 650,000.00		$ 600,000.00		$ (390,000.00)		$ (490,000.00)		$ 1.73	$ 0.36	$ (0.17)
Weighted Average Number of Shares Outstanding, Basic	429.6		437.2		450.6		449.8		451.1		452.1		451.4		436.3		441.8	447.7	437.7
Weighted Average Number of Shares Outstanding, Diluted	442.6	[1]	450.8	[1]	467.9	[1]	478.6	[1]	486.1	[1]	490.6	[1]	489.0	[1]	493.1	[1]	460.2	490.6	465.9
Convertible Preferred Stock Converted to Other Securities													$ 21.2

[1] [1]Weighted average common shares outstanding and dilutive potential common shares are used in the calculation of diluted earnings (losses) per common share in periods of losses when the impact is dilutive to income from continuing operations, net of tax, available to common shareholders.