Parent Company Financials - Condensed Statements of Cash Flows (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Cash Flow Statements, Captions [Line Items]
Net (loss) income	$ (293,425,000)	$ (23,065,000)	$ 6,061,000	$ (19,328,000)	$ (256,075,000)	$ 6,316,000	$ 17,644,000	$ 31,294,000	$ (329,757,000)	$ (200,821,000)	$ 145,206,000
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Accounts payable and accrued expenses									21,024,000	26,907,000	43,654,000
Net cash provided by operating activities									144,046,000	310,706,000	222,013,000
Investing activities:
Net cash used in investing activities									(120,393,000)	(1,066,879,000)	(491,529,000)
Financing activities:
Repurchase of common stock									0	(148,469,000)	(25,022,000)
Proceeds from options exercised									128,000	61,000	798,000
Tax payments related to shares withheld for vested restricted stock and stock units									(2,993,000)	(4,383,000)	(4,379,000)
Contributions from non-controlling interest									4,554,000	7,497,000	0
Net cash (used in) provided by financing activities									(40,411,000)	574,104,000	(57,142,000)
Net decrease in cash and cash equivalents									(16,758,000)	(182,069,000)	(326,658,000)
Cash and cash equivalents, beginning of period				202,498,000				384,567,000	202,498,000	384,567,000	711,225,000
Cash and cash equivalents, end of period	185,740,000				202,498,000				185,740,000	202,498,000	384,567,000
Cash (received) paid during the period for:
Interest									(87,286,000)	(66,769,000)	(24,490,000)
Cash dividends paid to the parent by its consolidated entities									0	0	0
Parent Company
Condensed Cash Flow Statements, Captions [Line Items]
Net (loss) income									(329,757,000)	(200,821,000)	145,206,000
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Undistributed loss (income) from equity method investment, net									330,617,000	202,655,000	(143,057,000)
Accounts payable and accrued expenses									(88,000)	(295,000)	48,000
Net cash provided by operating activities									772,000	1,539,000	2,197,000
Investing activities:
Investment in subsidiary									0	0	(143,654,000)
Net cash used in investing activities									0	0	(143,654,000)
Financing activities:
Dividends paid									(18,592,000)	(19,912,000)	(20,377,000)
Repurchase of common stock									0	(148,469,000)	(25,022,000)
Proceeds from options exercised									128,000	61,000	798,000
Tax payments related to shares withheld for vested restricted stock and stock units									(2,993,000)	(4,383,000)	(4,379,000)
Contributions from non-controlling interest									4,554,000	7,497,000	0
Net financing activities with subsidiaries									(39,171,000)	40,171,000	(113,294,000)
Net cash (used in) provided by financing activities									(56,074,000)	(125,035,000)	(162,274,000)
Net decrease in cash and cash equivalents									(55,302,000)	(123,496,000)	(303,731,000)
Cash and cash equivalents, beginning of period				$ 107,151,000				$ 230,647,000	107,151,000	230,647,000	534,378,000
Cash and cash equivalents, end of period	$ 51,849,000				$ 107,151,000				51,849,000	107,151,000	230,647,000
Cash (received) paid during the period for:
Interest									$ (1,440,000)	$ (2,784,000)	$ (3,853,000)