Consolidated Statement of Changes in Stockholders Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss)/Income [Member]
Beginning Balance at Dec. 31, 2014	$ 902,215	$ 496	$ 111,659	$ 906,010	$ (115,950)
Beginning Balance, Shares at Dec. 31, 2014	49,577	49,577
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	58,135			58,135
Foreign currency translation adjustment	(62,699)				(62,699)
Vesting of nonvested shares, shares		221
Vesting of nonvested shares		2	(2)
Repurchase and cancellation of common stock, shares		1,478
Repurchase and cancellation of common stock	77,802	15	77,787	0	0
Amortization of share-based compensation	3,636		3,636
Income tax benefit from share-based compensation	4,127		4,127
Employee stock relinquished for payment of taxes	(10,294)		(10,294)
Ending Balance at Mar. 31, 2015	$ 817,318	$ 483	$ 31,339	$ 964,145	$ (178,649)
Ending Balance, Shares at Mar. 31, 2015	48,320	48,320