CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2012	$ 534,357	$ 698	$ 534,487	$ 199,987	$ (186,784)	$ (14,031)
Net income	63,868			63,868
Other comprehensive (loss) income	(9,284)					(9,284)
Stock-based compensation	13,572		13,572
Shares issued and forfeited, net, under stock plans including income tax benefits	28,315		(5,362)		33,677
Repurchase of common stock	(80,912)				(80,912)
Repurchase of restricted stock and performance shares for tax withholdings	(6,222)				(6,222)
Ending Balance at Dec. 31, 2013	543,694	698	542,697	263,855	(240,241)	(23,315)
Net income	67,560			67,560
Other comprehensive (loss) income	3,432					3,432
Stock-based compensation	11,045		11,045
Shares issued and forfeited, net, under stock plans including income tax benefits	30,794		(2,029)		32,823
Repurchase of common stock	(70,000)				(70,000)
Repurchase of restricted stock and performance shares for tax withholdings	(5,120)				(5,120)
Ending Balance at Dec. 31, 2014	581,405	698	551,713	331,415	(282,538)	(19,883)
Net income	85,436			85,436
Other comprehensive (loss) income	(51,693)					(51,693)
Stock-based compensation	18,380		18,380
Shares issued and forfeited, net, under stock plans including income tax benefits	20,142		(14,089)		34,231
Repurchase of restricted stock and performance shares for tax withholdings	(4,649)				(4,649)
Ending Balance at Dec. 31, 2015	654,400	702	561,379	$ 416,851	$ (252,956)	$ (71,576)
Issuance of 476,750 shares under stock plan portion of PAY.ON acquisition agreement		3	(3)
Issuance of 227,917 shares of common stock for acquisition of PAY.ON	$ 5,379	$ 1	$ 5,378