Restatement of Previously Issued Financial Statements - Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accumulated depreciation, depletion and amortization	$ (310,176)	$ (274,374)
Net property and equipment	617,753	570,270
Deferred tax assets, net	1,662	0
Total assets	642,258	591,808
Deferred tax liabilities, net	0	4,769
Total long-term liabilities	374,402	324,162
Accumulated deficit	(151,966)	(113,836)
Total stockholders' equity	165,158	$ 203,690
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accumulated depreciation, depletion and amortization	(294,049)
Net property and equipment	633,880
Deferred tax assets, net	0
Total assets	656,723
Deferred tax liabilities, net	106
Total long-term liabilities	374,508
Accumulated deficit	(137,608)
Total stockholders' equity	179,516
Correction
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Accumulated depreciation, depletion and amortization	(16,127)
Net property and equipment	(16,127)
Deferred tax assets, net	1,662
Total assets	(14,465)
Deferred tax liabilities, net	(106)
Total long-term liabilities	(106)
Accumulated deficit	(14,358)
Total stockholders' equity	$ (14,358)