Consolidated Statements Of Operations And Comprehensive Income (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deferred income tax (benefit) expense for unrealized gains on investments arising during the period	$ (265)	$ 3,035	$ 10,209