Debt - Interest Rates (Details)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
New First Lien Facility
Debt Instrument [Line Items]
Commitment fee percentage	40.00%
New First Lien Facility | Minimum
Debt Instrument [Line Items]
Interest rate	4.91%
New First Lien Facility | Maximum
Debt Instrument [Line Items]
Interest rate	5.55%
New First Lien Facility | Weighted Average
Debt Instrument [Line Items]
Interest rate	5.44%
Ultraco Debt Facility
Debt Instrument [Line Items]
Interest rate	4.64%
Commitment fee percentage	40.00%
Ultraco Debt Facility | Weighted Average
Debt Instrument [Line Items]
Interest rate	5.29%
First Lien Facility
Debt Instrument [Line Items]
Commitment fee percentage		40.00%
First Lien Facility | Minimum
Debt Instrument [Line Items]
Interest rate		4.77%
First Lien Facility | Maximum
Debt Instrument [Line Items]
Interest rate		4.99%
First Lien Facility | Weighted Average
Debt Instrument [Line Items]
Interest rate		5.31%
Second Lien Facility
Debt Instrument [Line Items]
Interest rate		15.00%
Second Lien Facility | Weighted Average
Debt Instrument [Line Items]
Interest rate		17.05%
Senior Subordinated Notes | Norwegian Bond Debt Facility
Debt Instrument [Line Items]
Interest rate	8.25%
Senior Subordinated Notes | Norwegian Bond Debt Facility | Weighted Average
Debt Instrument [Line Items]
Interest rate	8.87%