Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock Shares [Member]	Treasury Stock-Common [Member]	Capital in Excess of Par Value [Member]	Retained Earnings [Member]	Non-Redeemable Preferred Stock [Member]
Balance at Dec. 31, 2016	$ 492,513	$ 3,128	$ (20,088)	$ 192,172	$ 314,301	$ 3,000
Balance, shares at Dec. 31, 2016		31,281	(3,005)
Cumulative effect of change in accounting principle	1,060				1,060
Net loss	(29,217)				(29,217)
Dividend accrued on redeemable preferred stock	(23,443)				(23,443)
Accretion of redeemable preferred stock	(6,487)				(6,487)
Stock-based compensation	5,099			5,099
Restricted stock granted from treasury stock	(1,361)		$ 1,814	(3,175)
Restricted stock granted from treasury stock, shares			317
Other	32		$ 172	(140)
Other, Shares			26
Balance at Dec. 31, 2017	438,196	$ 3,128	$ (18,102)	193,956	256,214	3,000
Balance, shares at Dec. 31, 2017		31,281	(2,662)
Net loss	(72,226)				(72,226)
Dividend accrued on redeemable preferred stock	(26,840)				(26,840)
Accretion of redeemable preferred stock	(3,375)				(3,375)
Stock-based compensation	8,358			8,358
Restricted stock granted from treasury stock	(1,936)		$ 1,916	(3,852)
Restricted stock granted from treasury stock, shares			224
Other	20			20
Other, Shares		2
Balance at Dec. 31, 2018	342,197	$ 3,128	$ (16,186)	198,482	153,773	3,000
Balance, shares at Dec. 31, 2018		31,283	(2,438)
Net loss	(63,417)				(63,417)
Dividend accrued on redeemable preferred stock	(30,729)				(30,729)
Accretion of redeemable preferred stock	(1,995)				(1,995)
Stock-based compensation	2,220			2,220
Restricted stock granted from treasury stock	(949)		$ 2,920	(3,869)
Restricted stock granted from treasury stock, shares			428
Balance at Dec. 31, 2019	$ 247,327	$ 3,128	$ (13,266)	$ 196,833	$ 57,632	$ 3,000
Balance, shares at Dec. 31, 2019		31,283	(2,010)