Consolidated Statements of Changes in Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2019	$ (697,223)	$ (25)	$ 2,157	$ 810,856	$ (14,024)	$ 101,741
Balance (in shares) at Dec. 31, 2019			21,573		930
Net income (loss)	(16,008)					(16,008)
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net				(32)	$ 104	72
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)					(6)
Stock-based compensation expense				3		3
Balance at Mar. 31, 2020	(713,231)	(25)	$ 2,157	810,827	$ (13,920)	85,808
Balance (in shares) at Mar. 31, 2020			21,573		924
Balance at Dec. 31, 2019	(697,223)	(25)	$ 2,157	810,856	$ (14,024)	101,741
Balance (in shares) at Dec. 31, 2019			21,573		930
Net income (loss)						(30,262)
Balance at Sep. 30, 2020	(729,286)	(25)	$ 2,157	809,189	$ (11,806)	70,229
Balance (in shares) at Sep. 30, 2020			21,573		789
Balance at Dec. 31, 2019	(697,223)	(25)	$ 2,157	810,856	$ (14,024)	101,741
Balance (in shares) at Dec. 31, 2019			21,573		930
Balance at Dec. 31, 2020	(736,639)	(25)	$ 2,157	807,582	$ (10,200)	62,875
Balance (in shares) at Dec. 31, 2020			21,573		688
Balance at Mar. 31, 2020	(713,231)	(25)	$ 2,157	810,827	$ (13,920)	85,808
Balance (in shares) at Mar. 31, 2020			21,573		924
Net income (loss)	(9,911)					(9,911)
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net				(1,718)	$ 1,790	72
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)					(114)
Stock-based compensation expense				146		146
Change in accounting at ownership interests	(1,801)					(1,801)
Balance at Jun. 30, 2020	(724,943)	(25)	$ 2,157	809,255	$ (12,130)	74,314
Balance (in shares) at Jun. 30, 2020			21,573		810
Net income (loss)	(4,343)					(4,343)
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net				(251)	$ 324	73
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)					(21)
Stock-based compensation expense				185		185
Balance at Sep. 30, 2020	(729,286)	(25)	$ 2,157	809,189	$ (11,806)	70,229
Balance (in shares) at Sep. 30, 2020			21,573		789
Balance at Dec. 31, 2020	(736,639)	(25)	$ 2,157	807,582	$ (10,200)	62,875
Balance (in shares) at Dec. 31, 2020			21,573		688
Net income (loss)	17,625					17,625
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net				(593)	$ 963	370
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)					(58)
Stock-based compensation expense				122		122
Balance at Mar. 31, 2021	(719,014)	(25)	$ 2,157	807,111	$ (9,237)	80,992
Balance (in shares) at Mar. 31, 2021			21,573		630
Balance at Dec. 31, 2020	(736,639)	(25)	$ 2,157	807,582	$ (10,200)	62,875
Balance (in shares) at Dec. 31, 2020			21,573		688
Net income (loss)						35,638
Balance at Sep. 30, 2021	(701,001)	(25)	$ 2,157	806,550	$ (9,688)	97,993
Balance (in shares) at Sep. 30, 2021			21,573		777
Balance at Mar. 31, 2021	(719,014)	(25)	$ 2,157	807,111	$ (9,237)	80,992
Balance (in shares) at Mar. 31, 2021			21,573		630
Net income (loss)	(320)					(320)
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net				(839)	$ 976	137
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)					(73)
Stock-based compensation expense				175		175
Repurchases of common stock					$ (1,588)	(1,588)
Repurchases of common stock (in shares)					229
Balance at Jun. 30, 2021	(719,334)	(25)	$ 2,157	806,447	$ (9,849)	79,396
Balance (in shares) at Jun. 30, 2021			21,573		786
Net income (loss)	18,333					18,333
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net				(98)	$ 212	114
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)					(16)
Stock-based compensation expense				201		201
Repurchases of common stock					$ (51)	(51)
Repurchases of common stock (in shares)					7
Balance at Sep. 30, 2021	$ (701,001)	$ (25)	$ 2,157	$ 806,550	$ (9,688)	$ 97,993
Balance (in shares) at Sep. 30, 2021			21,573		777