Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Earnings	Accumulated Other Comprehensive 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)	22,529			21,827		702
Other comprehensive (loss) gain, net of tax	16,063				15,893	170
Change in fair value of redeemable noncontrolling interest	(12,011)			(12,011)
Purchase of noncontrolling interest	3,424		3,424
Issuance of share-based awards, net of shares withheld for employee taxes (shares)		111
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes	(2,350)	$ 1	(2,351)
Stock-based compensation	2,276		2,276
Other	(89)		(89)
Balance at end of period (shares) at Mar. 31, 2018		25,912
Balance at end of period at Mar. 31, 2018	601,775	$ 259	45,906	626,130	(61,463)	(9,057)
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)	49,442			49,254		188
Other comprehensive (loss) gain, net of tax	5,550				5,123	427
Issuance of share-based awards, net of shares withheld for employee taxes (shares)		83
Exercise of stock options and issuance of share-based awards, net of shares withheld for employee taxes	(1,949)	$ 1	(1,950)
Stock-based compensation	1,826		1,826
Balance at end of period (shares) at Mar. 31, 2019		30,967
Balance at end of period at Mar. 31, 2019	$ 874,557	$ 310	$ 208,374	$ 769,443	$ (105,864)	$ 2,294