Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Common stock, shares issued under stock option plans	6,255	0
Tax benefit on exercise of stock options	$ 7	$ 0
Common stock, shares issued under employee stock purchase plan (shares)	10	20
Common stock, shares issued in connection with dividend reinvestment and stock purchase plan (shares)	1,272	3,100