Condensed Consolidated Statements of Shareholders' Equity (Deficit) (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Non-controlling Interest [Member]	Total
Balance at Dec. 31, 2019		$ 1,053,900	$ (1,002,700)	$ (20,600)	$ (24,900)	$ 25,600	$ 31,300
Balance, shares at Dec. 31, 2019	28,097				2,927
Net loss			(12,800)			(400)	(13,200)
Pension adjustments, net of tax				20,600			20,600
Balance at Mar. 31, 2020		1,053,900	(1,015,500)		$ (24,900)	25,200	38,700
Balance, shares at Mar. 31, 2020	28,097				2,927
Balance at Dec. 31, 2020		1,059,600	(1,065,000)		$ (24,900)	22,700	(7,600)
Balance, shares at Dec. 31, 2020	28,097				2,927
Net loss			(2,200)			(100)	(2,300)
Pension adjustments, net of tax
Balance at Mar. 31, 2021		$ 1,059,600	$ (1,067,200)		$ (24,900)	$ 22,600	$ (9,900)
Balance, shares at Mar. 31, 2021	28,097				2,927