Consolidated Statements Of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Total
Balance at December 31,2016	$ 57	$ (181,361)	$ 644,519	$ (25,206)	$ 196,468	$ 634,477
Balance, shares at Dec. 31, 2016	57,325	(10,339)
Comprehensive income				861	11,096	11,957
Issuances of common stock			1,914			1,914
Issuances of common stock, shares	119
Vesting of restricted stock units, net of forfeitures and tax withholdings			(1,233)			(1,233)
Vesting of restricted stock units, net of forfeitures and tax withholdings, shares	83
Share-based compensation expense			3,022			3,022
Repurchases of common stock		$ (4,961)				(4,961)
Repurchases of common stock, shares		(207)
Balance, shares at Mar. 31, 2017	57,527	(10,546)
Balance at December 31,2016						645,470
Cumulative-effect adjustment resulting from the adoption of ASU 2016-09 (see Note 2)			719		(425)	294
Balance at March 31, 2017	$ 57	$ (186,322)	$ 648,941	$ (24,345)	$ 207,139	$ 645,470