Consolidated Statements of Shareholders Equity (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended					12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Preferred Class A [Member]	Dec. 31, 2011 Preferred Class A [Member]	Dec. 31, 2010 Preferred Class A [Member]	Dec. 31, 2011 Accumulated Other Comprehensive Income (Loss) [Member]	Dec. 31, 2011 Maximum [Member]
Reclassification adjustment for gain realized on investments, tax		$ 1
Unrealized gain on investments, net of tax	$ 1	$ 1				$ 1	$ 1
Preferred stock, shares authorized			100,000	100,000	100,000
Preferred stock, par value
Preferred stock, stated value			$ 5,000	$ 5,000	$ 5,000
Preferred stock, shares issued
Preferred stock, shares outstanding