CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
CONDENSED CONSOLIDATING FINANCIAL INFORMATION
Net revenues	$ 325,662	$ 338,649
Operating expenses:
Cost of services and products (exclusive of depreciation and amortization)	137,755	148,319
Selling, general and administrative expenses	67,817	74,367
Depreciation and amortization	82,738	99,243
Income from operations	37,352	16,720
Other income (expense):
Interest expense, net of interest income	(32,095)	(34,283)
Gain on extinguishment of debt	234
Investment income	10,579	8,601
Other, net	4,594	(1,369)
Income (loss) before income taxes	20,664	(10,331)
Income tax expense (benefit)	5,041	(3,145)
Net income (loss)	15,623	(7,186)
Less: net income (loss) attributable to noncontrolling interest	76	79
Net income (loss) attributable to common shareholders	15,547	(7,265)
Total comprehensive income (loss) attributable to common shareholders	5,547	(13,711)
Eliminations
CONDENSED CONSOLIDATING FINANCIAL INFORMATION
Net revenues	(3,054)	(3,098)
Operating expenses:
Cost of services and products (exclusive of depreciation and amortization)	(2,948)	(2,988)
Selling, general and administrative expenses	(106)	(110)
Other income (expense):
Equity in earnings of subsidiaries, net	(45,359)	(1,379)
Income (loss) before income taxes	(45,359)	(1,379)
Net income (loss)	(45,359)	(1,379)
Net income (loss) attributable to common shareholders	(45,359)	(1,379)
Total comprehensive income (loss) attributable to common shareholders	(35,695)	4,041
Parent | Reportable legal entity
Operating expenses:
Selling, general and administrative expenses	1,078	1,655
Income from operations	(1,078)	(1,655)
Other income (expense):
Interest expense, net of interest income	(25)	(28)
Equity in earnings of subsidiaries, net	16,383	(6,076)
Other, net		(3)
Income (loss) before income taxes	15,280	(7,762)
Income tax expense (benefit)	(267)	(497)
Net income (loss)	15,547	(7,265)
Net income (loss) attributable to common shareholders	15,547	(7,265)
Total comprehensive income (loss) attributable to common shareholders	5,547	(13,711)
Subsidiary Issuer | Reportable legal entity
Operating expenses:
Selling, general and administrative expenses		(193)
Income from operations		193
Other income (expense):
Interest expense, net of interest income	(31,554)	(34,088)
Intercompany interest income (expense)	14,727	14,727
Gain on extinguishment of debt	234
Investment income	202	190
Equity in earnings of subsidiaries, net	28,769	7,242
Other, net		56
Income (loss) before income taxes	12,378	(11,680)
Income tax expense (benefit)	(4,005)	(5,604)
Net income (loss)	16,383	(6,076)
Net income (loss) attributable to common shareholders	16,383	(6,076)
Total comprehensive income (loss) attributable to common shareholders	6,383	(12,522)
Guarantors | Reportable legal entity
CONDENSED CONSOLIDATING FINANCIAL INFORMATION
Net revenues	317,054	329,278
Operating expenses:
Cost of services and products (exclusive of depreciation and amortization)	137,034	147,801
Selling, general and administrative expenses	64,846	70,600
Depreciation and amortization	80,258	96,781
Income from operations	34,916	14,096
Other income (expense):
Interest expense, net of interest income	(526)	(167)
Intercompany interest income (expense)	(14,711)	(14,708)
Investment income	10,377	8,411
Equity in earnings of subsidiaries, net	207	213
Other, net	4,538	(1,408)
Income (loss) before income taxes	34,801	6,437
Income tax expense (benefit)	8,442	1,756
Net income (loss)	26,359	4,681
Less: net income (loss) attributable to noncontrolling interest	76	79
Net income (loss) attributable to common shareholders	26,283	4,602
Total comprehensive income (loss) attributable to common shareholders	26,610	5,560
Non-Guarantors | Reportable legal entity
CONDENSED CONSOLIDATING FINANCIAL INFORMATION
Net revenues	11,662	12,469
Operating expenses:
Cost of services and products (exclusive of depreciation and amortization)	3,669	3,506
Selling, general and administrative expenses	1,999	2,415
Depreciation and amortization	2,480	2,462
Income from operations	3,514	4,086
Other income (expense):
Interest expense, net of interest income	10
Intercompany interest income (expense)	(16)	(19)
Other, net	56	(14)
Income (loss) before income taxes	3,564	4,053
Income tax expense (benefit)	871	1,200
Net income (loss)	2,693	2,853
Net income (loss) attributable to common shareholders	2,693	2,853
Total comprehensive income (loss) attributable to common shareholders	$ 2,702	$ 2,921