Condensed Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands		Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Noncontrolling Interest
Beginning balance at Dec. 31, 2018		$ 618,147	$ 62	$ 730,695	$ (364,195)	$ (328)	$ 253,208	$ (1,295)
Beginning balance (in shares) at Dec. 31, 2018			48,408		13,804
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of subsidiary shares to noncontrolling interest				22				(22)
Net income (loss)		(25,430)					(25,083)	(347)
Other comprehensive loss		178				178
Other	[1]	(2,859)					(2,859)
Cash dividends paid on common stock ($0.20 per share)		(9,822)					(9,822)
Issuance of common stock in connection with exercise of stock options		252		252
Issuance of common stock in connection with exercise of stock options (in shares)			14
Issuance of common stock in connection with employee stock purchase plan		3,111		3,111
Issuance of common stock in connection with employee common stock purchase plan (in shares)			227
Issuance of restricted stock, net of shares canceled		1	$ 1
Issuance of restricted stock, net of shares canceled (in shares)			698
Repurchases of common stock, shares exchanged		(3,131)			$ (3,131)
Repurchases of common stock, shares exchanged (in shares)			(138)		138
Stock-based compensation expense		7,623		7,623
Ending balance at Mar. 31, 2019		588,070	$ 63	741,703	$ (367,326)	(150)	215,444	(1,664)
Ending balance (in shares) at Mar. 31, 2019			49,209		13,942
Beginning balance at Dec. 31, 2019		545,100	$ 64	768,284	$ (368,701)	(53)	148,317	(2,811)
Beginning balance (in shares) at Dec. 31, 2019			49,620		14,002
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of subsidiary shares to noncontrolling interest				(3)				3
Net income (loss)		18,785					19,336	(551)
Other comprehensive loss		(274)				(274)
Cash dividends paid on common stock ($0.20 per share)		(10,036)					(10,036)
Issuance of common stock in connection with employee stock purchase plan		3,232		3,232
Issuance of common stock in connection with employee common stock purchase plan (in shares)			236
Issuance of restricted stock, net of shares canceled		1	$ 1
Issuance of restricted stock, net of shares canceled (in shares)			858
Repurchases of common stock, shares exchanged		(3,144)			$ (3,144)
Repurchases of common stock, shares exchanged (in shares)			(184)		184
Stock-based compensation expense		7,987		7,987
Ending balance at Mar. 31, 2020		$ 561,651	$ 65	$ 779,500	$ (371,845)	$ (327)	$ 157,617	$ (3,359)
Ending balance (in shares) at Mar. 31, 2020			50,530		14,186

[1] Refer to “Note 1 – The Company and Basis of Presentation.”