Condensed Consolidated Statement of Shareholders' Equity (Unaudited) (USD $) In Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock, At Cost [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Comprehensive Income [Member]
Balances at Dec. 31, 2010	$ 409,268	$ 389	$ 181,519	$ (24,947)	$ 253,526	$ (1,219)
Balances (in shares) at Dec. 31, 2010		36,755
Stock-based compensation expense			1,243
Issuance of restricted stock			(1,371)	1,507
Issuance of restricted stock (in shares)		126
Exercise of stock options			(523)	728
Exercise of stock options (in shares)		61
Income tax benefit on stock-based compensation			247
Change in cumulative translation adjustment						(1,893)	(1,893)
Net income	39,754				39,754		39,754
Total comprehensive income							37,861
Balances at Sep. 30, 2011	$ 439,985	$ 389	$ 180,030	$ (30,602)	$ 293,280	$ (3,112)
Balances (in shares) at Sep. 30, 2011		36,392