Organization, Basis of Presentation and Significant Accounting Policies (Details 4) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities	$ 315,913	$ 299,895
Net cash used in investing activities	(319,280)	(108,880)
Net cash used in financing activities	72,868	(152,272)
Net increase in cash, cash equivalents and restricted cash	69,501	38,743
Cash, cash equivalents, beginning of period	67,088
Cash and cash equivalents and restricted cash, beginning of period	201,906	329,977
Cash, cash equivalents, end of period	137,244	121,705
Cash and cash equivalents and restricted cash, end of period	$ 271,407	368,720
Scenario, Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities		293,462
Net cash used in investing activities		(235,347)
Net cash used in financing activities		(151,404)
Net (decrease) increase in cash, cash equivalents		(93,289)
Cash, cash equivalents, beginning of period		214,994
Cash, cash equivalents, end of period		121,705
Impact of ASU 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by operating activities		6,433
Net cash used in investing activities		126,467
Net cash used in financing activities		(868)
Net (decrease) increase in cash, cash equivalents		93,289
Net increase in cash, cash equivalents and restricted cash		38,743
Cash, cash equivalents, beginning of period		(214,994)
Cash and cash equivalents and restricted cash, end of period		$ 247,015