Condensed Consolidated Statement Of Changes In Stockholders' Equity (USD $) In Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance at beginning of period at Dec. 31, 2010	$ 665	$ 355,869	$ (1,480)	$ 61,979	$ (163,216)	$ 253,817
Shares at beginning of period at Dec. 31, 2010	66,542				24,823
Issuance of restricted stock, in shares	1,604
Exercise of stock options and stock appreciation rights, in shares	368
Issuance of restricted stock	16	(16)
Exercise of stock options and stock appreciation rights	4	2,590
Income tax benefit from stock-based compensation		1,227
Employee stock purchase plan		269			231	500
Employee stock purchase plan - shares					(34)
Stock-based compensation expense		8,746				8,746
Pension and postretirement plans, net of tax			45			45
Open market repurchases of common stock - shares					5,484
Open market repurchases of common stock					(56,364)
Net income				20,071		20,071
Shares repurchased for minimum tax withholding on restricted stock, stock option exercises and stock appreciation rights, in shares					90
Shares repurchased for minimum tax withholding on restricted stock, stock option exercises and stock appreciation rights					(1,585)	1,585
Shares tendered in payment of the exercise price of stock options, in shares					131
Shares tendered in payment of the exercise price of stock options					(2,401)	(2,401)
Balance at end of period at Sep. 30, 2011	$ 685	$ 368,685	$ (1,435)	$ 82,050	$ (223,335)	$ 226,650
Shares at end of period at Sep. 30, 2011	68,514				30,494