CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Thousands	Common stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total
Balance at Dec. 31, 2014	$ 46	$ 460,576	$ (6,462)	$ (370,366)	$ 83,794
Balance (in shares) at Dec. 31, 2014	46,398,729
Increase (Decrease) in Stockholders' Equity
Forfeitures of shares granted to employees (in shares)	(47,705)
Equity-based compensation		12,554			12,554
Foreign currency translation			(8,231)		(8,231)
Issuances of common stock (in shares)	62,900
Exercises of options		423			423
Exercises of options (in shares)	27,676
Common stock purchases and retirement	$ (1)	(39,394)			(39,395)
Common stock purchases and retirement (in shares)	(1,242,882)
Excess income tax benefit		2			2
Dividends paid				(66,314)	(66,314)
Net income (loss)				4,896	4,896
Balance at Dec. 31, 2015	$ 45	434,161	(14,693)	(431,784)	(12,271)
Balance (in shares) at Dec. 31, 2015	45,198,718
Increase (Decrease) in Stockholders' Equity
Cumulative-effect adjustment from adoption of ASU 2017-09				6,160	6,160
Forfeitures of shares granted to employees (in shares)	(3,824)
Equity-based compensation		11,910			11,910
Foreign currency translation			(2,500)		(2,500)
Issuances of common stock (in shares)	358,130
Exercises of options		1,220			1,220
Exercises of options (in shares)	53,245
Common stock purchases and retirement		(4,492)			(4,492)
Common stock purchases and retirement (in shares)	(127,482)
Dividends paid				(68,210)	(68,210)
Net income (loss)				14,929	14,929
Balance at Dec. 31, 2016	$ 45	442,799	(17,193)	(478,905)	$ (53,254)
Balance (in shares) at Dec. 31, 2016	45,478,787				45,478,787
Increase (Decrease) in Stockholders' Equity
Forfeitures of shares granted to employees (in shares)	(10,181)
Equity-based compensation		14,504			$ 14,504
Foreign currency translation			12,593		12,593
Issuances of common stock	$ 1				1
Issuances of common stock (in shares)	499,654
Exercises of options		1,222			1,222
Exercises of options (in shares)	39,289
Common stock purchases and retirement		(1,829)			(1,829)
Common stock purchases and retirement (in shares)	(46,750)
Dividends paid				(81,657)	(81,657)
Net income (loss)				5,876	5,876
Balance at Dec. 31, 2017	$ 46	$ 456,696	$ (4,600)	$ (554,686)	$ (102,544)
Balance (in shares) at Dec. 31, 2017	45,960,799				45,960,799