Business Segment Information - Reconciliation of Segment Profit to Income Before Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Reconciliation of segment profit to income before income taxes
(Loss) income from continuing operations before income taxes	$ 747	$ (19,626)	$ 32,502	$ (4,154)
Stock compensation expense	5,974	5,442	19,384	17,831
Depreciation and amortization	23,671	24,730	67,613	71,976
Interest expense	5,969	7,286	18,629	24,239
Interest and other income	(299)	(349)	(848)	(2,119)
Special charges and other	1,914	16,599	8,119	24,908
Segment Profit (Loss)	$ 37,976	$ 34,082	$ 145,399	$ 132,681