CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 325,142	$ 155,561
Accounts receivable, net of allowance for credit losses	125,677	137,646
Income tax receivable	1,072	1,072
Prepaid expenses and other current assets	48,574	46,382
Total current assets	500,465	340,661
Property, plant and equipment, net	1,772,678	1,760,152
Investments	110,801	111,665
Goodwill	1,035,274	1,035,274
Customer relationships, net	103,522	113,418
Other intangible assets	10,590	10,557
Other assets	140,490	135,573
Total assets	3,673,820	3,507,300
Current liabilities:
Accounts payable	27,174	25,283
Advance billings and customer deposits	49,144	49,544
Accrued compensation	64,971	74,957
Accrued interest	41,439	21,194
Accrued expense	86,978	81,931
Current portion of long-term debt and finance lease obligations	5,018	17,561
Total current liabilities	274,724	270,470
Long-term debt and finance lease obligations	2,105,779	1,932,666
Deferred income taxes	167,096	171,021
Pension and other post-retirement obligations	291,273	300,373
Convertible security interest	241,027	238,701
Contingent payment rights	180,829	123,241
Other long-term liabilities	80,586	81,600
Total liabilities	3,341,314	3,118,072
Commitments and contingencies (Note 13)
Shareholders' equity:
Common stock, par value $0.01 per share; 100,000,000 shares authorized, 79,983,431 and 79,227,607 shares outstanding as of March 31, 2021 and December 31, 2020, respectively	800	792
Additional paid-in capital	527,115	525,673
Accumulated deficit	(96,613)	(34,514)
Accumulated other comprehensive loss, net	(105,507)	(109,418)
Noncontrolling interest	6,711	6,695
Total shareholders' equity	332,506	389,228
Total liabilities and shareholders' equity	$ 3,673,820	$ 3,507,300