Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Balance at beginning of period (shares) at Dec. 31, 2017		25,801
Balance at beginning of period at Dec. 31, 2017	$ 571,933	$ 258	$ 42,646	$ 616,314	$ (77,356)	$ (9,929)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	48,314			48,125		189
Other comprehensive (loss) gain, net of tax	(18,925)				(19,544)	619
Change in fair value of redeemable noncontrolling interest	7,419		19,430	(12,011)
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes (shares)		130
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes	(1,915)	$ 1	(1,916)
Stock-based compensation	5,417		5,417
Other	(181)		(181)
Purchase of noncontrolling interest	3,424		3,424
Balance at end of period (shares) at Jun. 30, 2018		25,931
Balance at end of period at Jun. 30, 2018	615,486	$ 259	68,820	652,428	(96,900)	(9,121)
Balance at beginning of period (shares) at Mar. 31, 2018		25,912
Balance at beginning of period at Mar. 31, 2018	601,775	$ 259	45,906	626,130	(61,463)	(9,057)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	25,785			26,298		(513)
Other comprehensive (loss) gain, net of tax	(34,988)				(35,437)	449
Change in fair value of redeemable noncontrolling interest	19,430		19,430
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes (shares)		19
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes	435		435
Stock-based compensation	3,141		3,141
Other	(92)		(92)
Balance at end of period (shares) at Jun. 30, 2018		25,931
Balance at end of period at Jun. 30, 2018	615,486	$ 259	68,820	652,428	(96,900)	(9,121)
Balance at beginning of period (shares) at Dec. 31, 2018		30,884
Balance at beginning of period at Dec. 31, 2018	819,688	$ 309	208,498	720,189	(110,987)	1,679
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	86,264			85,915		349
Other comprehensive (loss) gain, net of tax	(6,006)				(6,440)	434
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes (shares)		96
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes	(1,428)	$ 1	(1,429)
Stock-based compensation	5,407		5,407
Other	(968)		(968)
Balance at end of period (shares) at Jun. 30, 2019		30,980
Balance at end of period at Jun. 30, 2019	902,957	$ 310	211,508	806,104	(117,427)	2,462
Balance at beginning of period (shares) at Mar. 31, 2019		30,967
Balance at beginning of period at Mar. 31, 2019	874,557	$ 310	208,374	769,443	(105,864)	2,294
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	36,822			36,661		161
Other comprehensive (loss) gain, net of tax	(11,556)				(11,563)	7
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes (shares)		13
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes	521		521
Stock-based compensation	3,581		3,581
Other	(968)		(968)
Balance at end of period (shares) at Jun. 30, 2019		30,980
Balance at end of period at Jun. 30, 2019	$ 902,957	$ 310	$ 211,508	$ 806,104	$ (117,427)	$ 2,462