Condensed Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Common Stock	Paid-in Capital	Retained Earnings	Treasury Stock, at cost	Accumulated Other Comprehensive Income (Loss)	Total
Beginning Balance at Dec. 31, 2018	$ 250	$ 717,492	$ 527,666	$ (583,883)	$ 43,296	$ 704,821
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares			(8,111)			(8,111)
Total comprehensive income (loss)			72,741		3,094	75,835
Employee stock-based compensation		5,651				5,651
Purchase of common stock under share repurchase program				(78,249)		(78,249)
Ending Balance at Mar. 31, 2019	250	723,143	592,296	(662,132)	46,390	699,947
Beginning Balance at Dec. 31, 2018	250	717,492	527,666	(583,883)	43,296	704,821
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)						239,365
Ending Balance at Sep. 30, 2019	250	734,829	746,928	(816,882)	40,311	705,436
Beginning Balance at Mar. 31, 2019	250	723,143	592,296	(662,132)	46,390	699,947
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares			(7,696)			(7,696)
Total comprehensive income (loss)			62,840		398	63,238
Employee stock-based compensation		5,822				5,822
Purchase of common stock under share repurchase program				(63,392)		(63,392)
Warrants exercised		31				31
Ending Balance at Jun. 30, 2019	250	728,996	647,440	(725,524)	46,788	697,950
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares			(7,281)			(7,281)
Total comprehensive income (loss)			106,769		(6,477)	100,292
Employee stock-based compensation		5,833				5,833
Purchase of common stock under share repurchase program				(91,358)		(91,358)
Ending Balance at Sep. 30, 2019	250	734,829	746,928	(816,882)	40,311	705,436
Beginning Balance at Dec. 31, 2019	252	730,551	731,425	(827,381)	5,689	640,536
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares			(7,834)			(7,834)
Total comprehensive income (loss)			(25,299)		(17,403)	(42,702)
Employee stock-based compensation		4,045				4,045
Common stock withheld related to net share settlement of equity awards		(281)				(281)
Ending Balance at Mar. 31, 2020	252	734,315	698,292	(827,381)	(11,714)	593,764
Beginning Balance at Dec. 31, 2019	252	730,551	731,425	(827,381)	5,689	640,536
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee stock-based compensation		4,891				4,891
Common stock withheld related to net share settlement of equity awards		(50)				(50)
Dividend Equivalents earned on RSU grants			(59)			(59)
Ending Balance at Jun. 30, 2020	252	739,156	648,909	(827,381)	(13,154)	547,782
Beginning Balance at Dec. 31, 2019	252	730,551	731,425	(827,381)	5,689	640,536
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)						(280,548)
Ending Balance at Sep. 30, 2020	252	744,112	457,432	(827,381)	(8,769)	365,646
Beginning Balance at Mar. 31, 2020	252	734,315	698,292	(827,381)	(11,714)	593,764
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)			(49,324)		(1,440)	(50,764)
Ending Balance at Jun. 30, 2020	252	739,156	648,909	(827,381)	(13,154)	547,782
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)			(191,467)		4,385	(187,082)
Employee stock-based compensation		4,971				4,971
Common stock withheld related to net share settlement of equity awards		(15)				(15)
Dividend Equivalents earned on RSU grants			(10)			(10)
Ending Balance at Sep. 30, 2020	$ 252	$ 744,112	$ 457,432	$ (827,381)	$ (8,769)	$ 365,646