Consolidated Statements of Comprehensive Income (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Unrealized Gains (Losses) on Securities:
Unrealized holding gains (losses) arising during the period, incomoe tax effects	$ 2,255	$ (1,062)	$ 824
Reclassification adjustment for realized gains included in net income, income tax effects	$ (40)	$ (1,217)	$ (1,482)