Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Costs related to shareholder activism	$ 0	$ 19,369	$ 0	$ 19,369
Cumulative effect of adoption of ASC 842					$ (2,203)		$ (424,859)
ROU assets	153,156		153,156
Leasing liabilities	104,795		104,795
Deferred charges and other assets, net	(300,143)		(300,143)			$ (390,403)
Accounts payable and accrued expenses	52,894		52,894			59,392
Other accrued liabilities	253,221		253,221			$ 303,051
Finance lease liabilities	$ 14,990		$ 14,990
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of adoption of ASC 842					(2,203)
ROU assets					109,299
Leasing liabilities					109,299
Deferred charges and other assets, net					59,736
Accounts payable and accrued expenses					(5,978)
Other accrued liabilities					(4,342)
Finance lease liabilities					$ 15,268