Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Unrealized gains (losses) on investments arising during the period, deferred tax	$ 13,136	$ 17,776	$ 9,242
Reclassification adjustment for net realized (gains) losses included in net income, deferred tax	10,314	2,588	9,045
Non credit other-than-temporary impairments arising during the period, deferred tax	612	39	2,045
Reclassification adjustment for non credit other-than-temporary impairment losses recognized in net income, deferred tax	16	84	524
Change in foreign currency translation gains (losses), deferred tax	$ 521	$ 192	$ 157