Industry Segments - Corporate Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
General and administrative expense	$ 34,014	$ 36,295	$ 64,551	$ 70,572
Depreciation, amortization, and accretion	29,842	31,817	59,302	62,445
Interest expense, net	17,586	18,529	35,442	36,908
Warrants fair value adjustment			(326)	(1,113)
Other (income) expense, net	3,839	627	4,278	(324)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	37,130	8,201	47,361	26,875
Corporate Overhead [Member]
Segment Reporting Information [Line Items]
General and administrative expense	11,611	14,350	19,692	26,439
Depreciation, amortization, and accretion	175	172	372	340
Interest expense, net	4,749	5,696	10,204	11,038
Warrants fair value adjustment	11	(1,520)	(327)	(1,113)
Other (income) expense, net	363	605	412	286
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 16,909	$ 19,303	$ 30,353	$ 36,990