Quarterly report pursuant to Section 13 or 15(d)

Recent Accounting Pronouncements (Details)

v3.8.0.1
Recent Accounting Pronouncements (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Increase to net cash used in investing activities $ (306,871) $ (1,532,679)  
Accounting Standards Update 2016-18      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Increase in restricted cash     $ 185,000
Increase to net cash used in investing activities   $ 185,000