Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of adoption of ASC 842		$ (2,203)		$ (424,859)
ROU assets	$ 156,260
Leasing liabilities	107,115
Deferred charges and other assets, net	307,667		$ 390,403
Accounts payable and accrued expenses	59,024		59,392
Other accrued liabilities	244,649		$ 303,051
Finance lease liabilities	$ 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