Premium Deficiency Reserve (Details) (USD $)	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Dec. 31, 2012
Premium Deficiency Reserve [Abstract]
Present value of expected future paid losses and expenses, net of expected future premium	$ (808,000,000)		$ (903,000,000)		$ (840,000,000)
Established loss reserves	736,000,000		782,000,000		766,000,000
Net deficiency	(72,131,000)		(121,000,000)
Change in premium deficiency reserve, excluding prior period adjustments	2,000,000		14,000,000
Premium Deficiency Reserve [Roll Forward]
Premium Deficiency Reserve at beginning of period	(73,781,000)		(135,000,000)
Paid claims and loss adjustment expenses	58,000,000		76,000,000
Decrease in loss reserves	(30,000,000)		(44,000,000)
Premium earned	(23,000,000)		(28,000,000)
Effects of present valuing on future premiums, losses and expenses	(2,000,000)		0
Change in premium deficiency reserve to reflect actual premium, losses and expenses recognized	3,000,000		4,000,000
Change in premium deficiency reserve to reflect change in assumptions relating to future premiums, losses expenses and discount rate	(1,000,000)	[1]	10,000,000	[1]
Premium Deficiency Reserve at end of period	$ (72,131,000)		$ (121,000,000)

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