UNAUDITED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - 3 months ended Mar. 31, 2018 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Earnings
Balance at beginning of period at Dec. 31, 2017	$ 1,188,202	$ 565	$ 686,962	$ (172,407)	$ 673,082
Balance beginning of period (in shares) at Dec. 31, 2017		56,501
Increase (Decrease) in Stockholders' Equity
Net loss	(12,631)				(12,631)
Other comprehensive loss	(16,746)			(16,746)
Stock-based compensation	3,077		3,077
Issuance of restricted shares, net of shares remitted and tax withholdings	(548)	$ 0	(548)
Issuance of restricted shares, net of shares remitted and tax withholdings (in shares)		24
Repurchases of common stock	$ (14,264)	$ (3)	(14,261)
Repurchases of common stock (in shares)	(300)	(280)
Balance at end of period at Mar. 31, 2018	$ 1,145,526	$ 562	$ 675,230	$ (189,153)	658,887
Balance ending of period (in shares) at Mar. 31, 2018		56,245
Increase (Decrease) in Stockholders' Equity
Cumulative effect of change in accounting principle	$ (1,564)
Cumulative effect of change in accounting principle | Accounting Standards Update 2016-16					$ (1,564)