CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Deferred tax, change in net unrealized gains (losses) on investments	$ 15,143		$ (1,324)		$ 25,602
Deferred tax, change in net unrealized gains (losses) on investments	192		157		72
Disclosure of reclassification amount, net of tax:
Unrealized gains (losses) on investments arising during period	34,348		12,339		33,910
Reclassification adjustment for net realized gains (losses) included in net income	(4,807)		(16,797)		1,624
Reclassification adjustment for other-than-temporary impairment losses recognized in net income	(155)		974		14,486
Change in net unrealized gains (losses) on investments, net of tax	$ 29,386	[1]	$ (3,484)	[1]	$ 50,020	[1]

[1] Disclosure of reclassification amount, net of tax: Unrealized gains (losses) on investments arising during period $ 34,348 $ 12,339 $ 33,910 Reclassification adjustment for net realized gains (losses) included in net income (4,807 ) (16,797 ) 1,624 Reclassification adjustment for other-than-temporary impairment losses recognized in net income (155 ) 974 14,486 Change in net unrealized gains (losses) on investments, net of tax $ 29,386 $ (3,484 ) $ 50,020