Consolidated Statements of Shareholders' Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands		Total	Common Stock	Additional Paid-In Capital	Retained Deficit	Treasury Stock
Beginning Balance (in shares) at Dec. 31, 2019	[1]		2,096
Beginning Balance at Dec. 31, 2019		$ 14,379	$ 319	$ 190,386	$ (172,896)	$ (3,430)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock awards (cancellations), net (in shares)	[1]		3
Stock-based compensation		597		597
Net income (loss)		(47,181)			(47,181)
Ending Balance (in shares) at Mar. 31, 2020	[1]		2,093
Ending Balance at Mar. 31, 2020		(32,205)	$ 319	190,983	(220,077)	(3,430)
Beginning Balance (in shares) at Dec. 31, 2019	[1]		2,096
Beginning Balance at Dec. 31, 2019		14,379	$ 319	190,386	(172,896)	(3,430)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(274,898)
Ending Balance (in shares) at Sep. 30, 2020	[1]		2,096
Ending Balance at Sep. 30, 2020		(259,023)	$ 319	191,882	(447,794)	(3,430)
Beginning Balance (in shares) at Mar. 31, 2020	[1]		2,093
Beginning Balance at Mar. 31, 2020		(32,205)	$ 319	190,983	(220,077)	(3,430)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock awards (cancellations), net (in shares)	[1]		3
Stock-based compensation		478		478
Net income (loss)		(12,753)			(12,753)
Ending Balance (in shares) at Jun. 30, 2020	[1]		2,096
Ending Balance at Jun. 30, 2020		(44,480)	$ 319	191,461	(232,830)	(3,430)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		421		421
Net income (loss)		(214,964)			(214,964)
Ending Balance (in shares) at Sep. 30, 2020	[1]		2,096
Ending Balance at Sep. 30, 2020		(259,023)	$ 319	191,882	(447,794)	(3,430)
Beginning Balance (in shares) at Dec. 31, 2020	[1]		2,084
Beginning Balance at Dec. 31, 2020		(279,265)	$ 21	188,978	(468,264)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock awards (cancellations), net (in shares)	[1]		98
Restricted stock awards (cancellations), net			$ 1	(1)
Stock-based compensation		166		166
Net income (loss)		38,844			38,844
Ending Balance (in shares) at Mar. 31, 2021	[1]		2,182
Ending Balance at Mar. 31, 2021		(240,255)	$ 22	189,143	(429,420)	0
Beginning Balance (in shares) at Dec. 31, 2020	[1]		2,084
Beginning Balance at Dec. 31, 2020		(279,265)	$ 21	188,978	(468,264)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		124,432
Ending Balance (in shares) at Sep. 30, 2021	[1]		2,193
Ending Balance at Sep. 30, 2021		(153,564)	$ 22	190,246	(343,832)	0
Beginning Balance (in shares) at Mar. 31, 2021	[1]		2,182
Beginning Balance at Mar. 31, 2021		(240,255)	$ 22	189,143	(429,420)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock awards (cancellations), net (in shares)	[1]		12
Stock-based compensation		517		517
Net income (loss)		49,078			49,078
Ending Balance (in shares) at Jun. 30, 2021	[1]		2,194
Ending Balance at Jun. 30, 2021		(190,660)	$ 22	189,660	(380,342)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock awards (cancellations), net (in shares)	[1]		1
Stock-based compensation		586		586
Net income (loss)		36,510			36,510
Ending Balance (in shares) at Sep. 30, 2021	[1]		2,193
Ending Balance at Sep. 30, 2021		$ (153,564)	$ 22	$ 190,246	$ (343,832)	$ 0

[1] Prior period results and share amounts have been adjusted to reflect the fifteen-for-one Reverse Stock Split. See Note 9 - Equity.