Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - 9 months ended Sep. 30, 2015 - USD ($)	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	$ 63,000			$ 63,000
Beginning Balance, Issued Shares at Dec. 31, 2014	36,232,074	36,232,074
Beginning Balance, Treasury Shares at Dec. 31, 2014			(40,509)
Beginning Balance, Value at Dec. 31, 2014	$ 432,221,000	$ 3,619,000	$ (76,000)	137,101,000	$ 309,726,000	$ (18,149,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	57,604,000				57,604,000
Cumulative translation adjustment	(14,163,000)					(14,163,000)
Repurchase and retirement of common stock, Shares		(2,513,692)
Repurchase and retirement of common stock, Value	(68,793,000)	$ (252,000)		(68,541,000)
Vesting of restricted stock, Shares		91,011
Vesting of restricted stock, Value	0	$ 9,000		(9,000)
Exercise of stock options, Shares		56,250
Exercise of stock options, Value	1,117,000	$ 6,000		1,111,000
Share based compensation	1,244,000			1,244,000
Forfeiture of certain shares to satisfy exercise costs and the recipients income tax obligations related to stock options exercised and restricted stock vested, Shares		(38,040)
Forfeiture of certain shares to satisfy exercise costs and the recipients income tax obligations related to stock options exercised and restricted stock vested	(1,141,000)	$ (4,000)		(1,137,000)
Treasury Stock, Shares, Retired		(40,509)	40,509
Treasury Stock, Retired, Cost Method, Amount	0		$ 76,000	(76,000)
Dividends paid	$ (7,989,000)				(7,989,000)
Ending Balance, Issued Shares at Sep. 30, 2015	33,787,094	33,787,094
Ending Balance, Treasury Shares at Sep. 30, 2015			0
Ending Balance, Value at Sep. 30, 2015	$ 400,163,000	$ 3,378,000	$ 0	$ 69,756,000	$ 359,341,000	$ (32,312,000)