CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) (USD $) In Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]
Balance at Dec. 31, 2012	$ 240,905	$ 308	$ 133,207	$ (133,950)	$ 16	$ 241,324
Balance (shares) at Dec. 31, 2012		30,758
Purchase of treasury stock, at cost	(15,122)	0	0	(15,122)	0	0
Exercise of stock options	858	0	(494)	1,352	0	0
Income tax benefit from stock-based compensation, net	709	0	709	0	0	0
Stock-based compensation expense	5,602	0	877	4,725	0	0
Other	(577)	0	(50)	(527)	0	0
Dividends paid	(8,694)	0	0	0	0	(8,694)
Unrealized loss on marketable securities, net of tax	(19)	0	0	0	(19)	0
Net income	16,661	0	0	0	0	16,661
Balance at Jun. 30, 2013	$ 241,477	$ 308	$ 134,349	$ (142,468)	$ (3)	$ 249,291
Balance (shares) at Jun. 30, 2013		30,758