Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Comprehensive income:
Other comprehensive income (loss), tax	$ 203	$ (385)	$ 73
Cash dividends (in dollars per share)	$ 0.48	$ 0.48	$ 0.72
Issuance of common stock - nonvested shares (in shares)	11,925	10,914	28,847
Issuance of common stock - vested shares (in shares)	13,477	4,752	6,522