Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - 3 months ended Mar. 31, 2017 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning Balance at Dec. 31, 2016	$ 1,207,358	$ 420	$ 416,816	$ 941,001	$ (150,879)
Beginning Balance (in shares) at Dec. 31, 2016	42,037	42,037
Net income	$ 14,016			14,016
Other comprehensive income (loss):
Cumulative translation adjustment	7,370				7,370
Issuance of common stock in connection with:
Exercise of options (in shares)		39
Exercise of options	1,393		1,393
Restricted share grants, less net settled shares of 51 (in shares)		125
Restricted share grants, less net settled shares of 51	(2,115)	$ 1	(2,116)
Stock units issued under incentive compensation plan	1,547		1,547
Purchase and retirement of common stock (in shares)		(880)
Purchase and retirement of common stock	(36,918)	$ (8)	(36,910)
Cumulative effect due to adoption of new accounting standard	(3,189)			(3,189)
Share-based compensation	7,067		7,067
Ending Balance at Mar. 31, 2017	$ 1,196,529	$ 413	$ 387,797	$ 951,828	$ (143,509)
Ending Balance (in shares) at Mar. 31, 2017	41,321	41,321