Annual report pursuant to Section 13 and 15(d)

Property and Equipment - Schedule of Asset Retirement Obligation (Details)

v3.10.0.1
Property and Equipment - Schedule of Asset Retirement Obligation (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]      
Asset retirement obligation, beginning of period $ 75,100 $ 34,276  
Liabilities incurred 1,827 16,300  
Liabilities settled (719) (3,057)  
Accretion expense 4,119 1,611 $ 1,057
Revisions in estimated cash flows (375) 25,970  
Asset retirement obligation as of end of period 79,952 75,100 $ 34,276
Less current portion 0 120  
Asset retirement obligation, long-term $ 79,952 $ 74,980