Accrued Expenses and other current liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Liabilities, Current [Abstract]
Accrued interest	$ 19,604	$ 20,564
Accrued bonus	16,906	14,788
Accrued insurance	78,048	52,280
Accrued property and other taxes	18,675	17,379
Construction retainage	3,882	226
Other	39,209	25,859
Total	$ 176,324	$ 131,096