Premium Deficiency Reserve (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Premium Deficiency Reserve [Abstract]
Present value of expected future premium	$ 445,000,000		$ 494,000,000		$ 506,000,000
Present value of expected future paid losses and expenses	(1,285,000,000)		(1,455,000,000)		(1,760,000,000)
Net present value of future cash flows	(840,000,000)		(961,000,000)		(1,254,000,000)
Established loss reserves	766,000,000		826,000,000		1,075,000,000
Net deficiency	(73,781,000)		(134,817,000)		(179,000,000)
Discount rate utilized	1.30%		2.30%		2.50%
Change in premium deficiency reserve, excluding prior period adjustments	61,000,000		44,000,000		14,000,000
Premium Deficiency Reserve [Roll Forward]
Premium Deficiency Reserve at beginning of period	(134,817,000)		(179,000,000)		(193,000,000)
Adjustment to premium deficiency reserve	0	[1]	0	[1]	(37,000,000)	[1]
Adjusted premium deficiency reserve at beginning of period	(135,000,000)		(179,000,000)		(230,000,000)
Paid claims and loss adjustment expenses	279,000,000		334,000,000		426,000,000
Decrease in loss reserves	(60,000,000)		(249,000,000)		(425,000,000)
Premium earned	(102,000,000)		(120,000,000)		(128,000,000)
Effects of present valuing on future premiums, losses and expenses	(1,000,000)		(8,000,000)		(25,000,000)
Change in premium deficiency reserve to reflect actual premium, losses and expenses recognized	116,000,000		(43,000,000)		(152,000,000)
Change in premium deficiency reserve to reflect change in assumptions relating to future premiums, losses expenses and discount rate	(55,000,000)	[2]	87,000,000	[2]	203,000,000	[2]
Premium Deficiency Reserve at end of period	$ (73,781,000)		$ (134,817,000)		$ (179,000,000)

[1] In periods prior to 2010 an estimate of premium to be refunded in conjunction with claim payments was included in Loss Reserves. In 2010, we separately stated this liability in Premium deficiency reserve on the consolidated balance sheet. (See Note 3 - "Summary of Significant Accounting Policies - Revenue Recognition")

[2] A (negative) positive number for changes in assumptions relating to premiums, losses, expenses and discount rate indicates a (deficiency) redundancy of prior premium deficiency reserves.