Consolidated Statements of Comprehensive Income (Parentheticals) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Statement Of Income and Comprehensive Income [Abstract]
Unrealized holding gains arising during the period, tax expense (in dollars)	$ 391	$ 864
Reclassification adjustment for gains included in net income, tax expense (in dollars)	$ 346	$ 108