Consolidated Statements of Changes in Equity (USD $) In Millions, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance at Dec. 31, 2008	$ 3,556	$ 1,386	$ 1,560	$ 622	$ (12)
Beginning Balance, shares at Dec. 31, 2008		138,632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	376			376
Dividends declared on common stock	(305)			(305)
Net change in unrealized gains on investments, net of tax	(2)				(2)
Benefit obligations, net of tax	(2)				(2)
Proceeds from Contributions from Parent	250		250
Ending Balance at Dec. 31, 2009	3,873	1,386	1,810	693	(16)
Ending Balance, shares at Dec. 31, 2009		138,632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	441			441
Dividends declared on common stock	(305)			(305)
Net change in unrealized gains on investments, net of tax	0
Ending Balance at Dec. 31, 2010	4,009	1,386	1,810	829	(16)
Ending Balance, shares at Dec. 31, 2010	138,632,324	138,632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	437			437
Dividends declared on common stock	(306)			(306)
Net change in unrealized gains on investments, net of tax	0
Benefit obligations, net of tax	(4)				(4)
Ending Balance at Dec. 31, 2011	$ 4,136	$ 1,386	$ 1,810	$ 960	$ (20)
Ending Balance, shares at Dec. 31, 2011	138,632,324	138,632,000