Schedule 1 - Condensed Parent Company Financial Statements (Condensed Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 1,868,922	$ 3,627	$ 4,204	$ 3,763
Accounts receivable, net	67,137	65,825
Prepayments and other current assets	16,259	23,337
Total current assets	2,012,738	147,172
Deferred charges and other assets, net	42,652	39,237
Investment in subsidiaries	5,984	6,959
Total assets	9,361,985	6,964,496	6,332,463
Stockholders' equity	3,880,860	2,009,364
Long-term debt, excluding current portion, net of debt issuance costs	2,943,327	2,398,464
Current portion of long-term debt	105,051	144,545
Accounts payable	74,919	77,331
Accrued interest	29,818	23,300
Accrued taxes	22,775	22,234
Interest rate swap agreements		59,779
Other accrued liabilities	49,618	47,389
Total current liabilities	318,849	398,977
Other liabilities	102,465	97,182
Total liabilities and equity	9,361,985	6,964,496
Parent Company [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	1,864,993
Accounts receivable, net	442	38
Accounts receivable - affiliates	134,779	104,494
Prepayments and other current assets	4,661	14,321
Total current assets	2,004,875	118,853
Deferred charges and other assets, net	33,627	29,247
Notes receivable - affiliates	411,985	369,740
Deferred income tax asset	32,925	35,696
Investment in subsidiaries	2,697,504	2,510,120
Total assets	5,180,916	3,063,656
Stockholders' equity	3,880,860	2,009,364
Long-term debt, excluding current portion, net of debt issuance costs	1,081,507	758,206
Current portion of long-term debt	38,854	50,000
Accrued interest	7,054	3,236
Accounts payable - affiliates	32,350	39,879
Interest rate swap agreements		59,779
Other accrued liabilities	10,632	11,582
Total current liabilities	88,890	164,476
Other liabilities	129,659	131,610
Total liabilities and equity	$ 5,180,916	$ 3,063,656