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 on securities available-for-sale:
Unrealized holding gains arising during the year, income tax expense	$ 291	$ 1,872	$ 143
Reclassification adjustment for gain on liquidation of equity security included in securities available-for-sale, income tax expense	$ 71	$ 34	$ 1