UNAUDITED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - 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 income (loss)	(12,631)				(12,631)
Other comprehensive income	(16,746)			(16,746)
Stock-based compensation	3,077		3,077
Issuance of restricted shares, net of shares remitted and tax withholdings	(548)		(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)	(280)	(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
Balance at beginning of period at Dec. 31, 2018	1,169,756	$ 558	655,415	(223,371)	737,154
Balance beginning of period (in shares) at Dec. 31, 2018		55,847
Increase (Decrease) in Stockholders' Equity
Net income (loss)	976				976
Other comprehensive income	4,024			4,024
Stock-based compensation	5,809		5,809
Issuance of restricted shares, net of shares remitted and tax withholdings	(2,276)	$ 1	(2,277)
Issuance of restricted shares, net of shares remitted and tax withholdings (in shares)		78
Repurchases of common stock	$ (6,324)	$ (1)	(6,323)
Repurchases of common stock (in shares)	(97)	(97)
Balance at end of period at Mar. 31, 2019	$ 1,171,965	$ 558	$ 652,624	$ (219,347)	$ 738,130
Balance ending of period (in shares) at Mar. 31, 2019		55,828