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 (in shares)			21,573		914
Balance at Dec. 31, 2018	$ (731,105)	$ 0	$ 2,157	$ 810,928	$ (15,001)	$ 66,979
Balance (in shares) at Dec. 31, 2018			21,573		914
Net income (loss)	21,663	0	$ 0	0	$ 0	21,663
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net	0	0	$ 0	7	$ (156)	(149)
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)			0		83
Stock-based compensation expense	0	0	$ 0	417	$ 0	417
Balance (in shares)			21,573		914
Stock options exercised, net of tax withholdings	0	0	$ 0	0	$ 0	0
Stock options exercised, net of tax withholdings (in shares)			0		1
Other comprehensive income (loss)	0	(31)	$ 0	0	$ 0	(31)
Balance at Mar. 31, 2019	(709,442)	(31)	2,157	811,352	(15,157)	88,879
Balance at Dec. 31, 2018	(731,105)	0	$ 2,157	810,928	$ (15,001)	66,979
Balance (in shares) at Dec. 31, 2018			21,573		914
Net income (loss)						55,259
Balance (in shares)			21,573		914
Balance at Sep. 30, 2019	(675,846)	(25)	$ 2,157	810,649	$ (13,998)	122,937
Balance (in shares)			21,573		998
Balance at Mar. 31, 2019	(709,442)	(31)	$ 2,157	811,352	$ (15,157)	88,879
Balance (in shares) at Mar. 31, 2019			21,573		998
Net income (loss)	36,093	0	$ 0	0	$ 0	36,093
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net	0	0	$ 0	(1,220)	$ 1,189	(31)
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)			0		(77)
Stock-based compensation expense	0	0	$ 0	269	$ 0	269
Balance (in shares)			21,573		998
Other comprehensive income (loss)	0	6	$ 0	0	$ 0	6
Balance at Jun. 30, 2019	(673,349)	(25)	$ 2,157	810,401	$ (13,968)	125,216
Balance (in shares)			21,573		921
Balance (in shares) at Jun. 30, 2019			21,573		921
Net income (loss)	(2,497)	0	$ 0	0	$ 0	(2,497)
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net	0	0	$ 0	0	$ (30)	(30)
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)			0		7
Stock-based compensation expense	0	0	$ 0	248	$ 0	248
Balance (in shares)			21,573		921
Other comprehensive income (loss)	0	0	$ 0	0	$ 0	0
Balance at Sep. 30, 2019	(675,846)	(25)	$ 2,157	810,649	$ (13,998)	122,937
Balance (in shares)			21,573		928
Balance (in shares)			21,573		930
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)	0	$ 0	0	$ 0	(16,008)
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net	0	0	$ 0	(32)	$ 104	72
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)			0		(6)
Stock-based compensation expense	0	0	$ 0	3	$ 0	3
Balance (in shares)			21,573		930
Balance at Mar. 31, 2020	(713,231)	(25)	$ 2,157	810,827	$ (13,920)	85,808
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 (in shares)			21,573		930
Balance at Sep. 30, 2020	(729,286)	(25)	$ 2,157	809,189	$ (11,806)	70,229
Balance (in shares)			21,573		924
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)	0	$ 0	0	$ 0	(9,911)
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net	0	0	$ 0	(1,718)	$ 1,790	72
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)			0		(114)
Stock-based compensation expense	0	0	$ 0	146	$ 0	146
Change in accounting at ownership interests	(1,801)	0	$ 0	0	$ 0	(1,801)
Balance (in shares)			21,573		924
Balance at Jun. 30, 2020	(724,943)	(25)	$ 2,157	809,255	$ (12,130)	74,314
Balance (in shares)			21,573		810
Balance (in shares) at Jun. 30, 2020			21,573		810
Net income (loss)	(4,343)	0	$ 0	0	$ 0	(4,343)
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net	0	0	$ 0	(251)	$ 324	73
Restricted stock awards, forfeitures and shares repurchased for tax withholdings, net (in shares)			0		(21)
Stock-based compensation expense	0	0	$ 0	185	$ 0	185
Balance (in shares)			21,573		810
Balance at Sep. 30, 2020	$ (729,286)	$ (25)	$ 2,157	$ 809,189	$ (11,806)	$ 70,229
Balance (in shares)			21,573		789