UNAUDITED CONDENSED STATEMENTS OF CONSOLIDATED EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Warrants [Member]	Additional Paid in Capital [Member]	Accumulated Earnings (Deficit) [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2018	$ 416,558	$ 3	$ 4,788	$ 355,872	$ 55,895	$ 0
Net income (loss)	(31,477)	0	0	0	(31,477)	0
Costs incurred in conjunction with tender offer	(107)	0	0	(107)	0	0
Share-based compensation expense	1,443	0	0	1,443	0	0
Common stock repurchased and retired under the share repurchase program	(920)	0	0	(920)	0	0
Balance at Mar. 31, 2019	385,497	3	4,788	356,288	24,418	0
Balance at Dec. 31, 2018	416,558	3	4,788	355,872	55,895	0
Net income (loss)	(7,679)
Balance at Sep. 30, 2019	480,045	209	4,790	435,019	40,027	0
Balance at Mar. 31, 2019	385,497	3	4,788	356,288	24,418	0
Net income (loss)	18,641	0	0	0	18,641	0
Share-based compensation expense	1,479	0	0	1,479	0	0
Common stock repurchased and retired under the share repurchase program	(331)	0	0	(331)	0	0
Restricted shares repurchased	(199)	0	0	(199)	0	0
Balance at Jun. 30, 2019	405,087	3	4,788	357,237	43,059	0
Net income (loss)	5,157	0	0	0	5,157	0
Equity transactions related to the Merger	91,246	206	2	91,038	0	0
Treasury shares acquired in the Merger	(2,723)	0	0	0	0	(2,723)
Retirement of treasury shares	0	0	0	(2,723)	0	2,723
Share-based compensation expense	1,151	0	0	1,151	0	0
Common stock repurchased and retired under the share repurchase program	(12,000)	0	0	(12,000)	0	0
Restricted shares repurchased	(115)	0	0	(115)	0	0
Dividends	(8,189)	0	0	0	(8,189)	0
Other	431	0	0	431	0	0
Balance at Sep. 30, 2019	480,045	209	4,790	435,019	40,027	$ 0
Balance at Dec. 31, 2019	434,207	209	4,790	424,399	4,809
Net income (loss)	(367,199)	0	0	0	(367,199)
Share-based compensation expense	(1,112)	0	0	(1,112)	0
Restricted shares repurchased	(14)	0	0	(14)	0
Dividends	(3,786)	0	0	0	(3,786)
Balance at Mar. 31, 2020	62,096	209	4,790	423,273	(366,176)
Balance at Dec. 31, 2019	434,207	209	4,790	424,399	4,809
Net income (loss)	(426,220)
Balance at Sep. 30, 2020	4,036	209	4,788	424,236	(425,197)
Balance at Mar. 31, 2020	62,096	209	4,790	423,273	(366,176)
Net income (loss)	(41,336)	0	0	0	(41,336)
Share-based compensation expense	480	0	0	480	0
Expiration of warrants	0	0	(2)	2	0
Restricted shares repurchased	(20)	0	0	(20)	0
Other	35	0	0	35	0
Balance at Jun. 30, 2020	21,255	209	4,788	423,770	(407,512)
Net income (loss)	(17,685)	0	0	0	(17,685)
Share-based compensation expense	471	0	0	471	0
Restricted shares repurchased	(5)	0	0	(5)	0
Balance at Sep. 30, 2020	$ 4,036	$ 209	$ 4,788	$ 424,236	$ (425,197)