Investments (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Realized pretax gains-losses-on the sale of investments excluding temporary impairment losses
Gains	$ 10,051	$ 14,259	$ 14,688
Losses	(6,398)	(2,155)	(2,612)
Net fixed income securities	3,657	12,212	11,518
Net other investments	(4)	(108)	558
Net realized investment gain (loss)	3,653	12,104	12,076
Fixed income securities [Member]
Realized pretax gains-losses-on the sale of investments excluding temporary impairment losses
Gains	10,045	14,207	13,969
Losses	(6,388)	(1,995)	(2,451)
Other Investments [Member]
Realized pretax gains-losses-on the sale of investments excluding temporary impairment losses
Gains	6	52	719
Losses	$ (10)	$ (160)	$ (161)