XML 44 R31.htm IDEA: XBRL DOCUMENT v3.10.0.1
Revenue from Contracts with Customers (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Dec. 31, 2017
Capitalized Contract Cost [Line Items]          
Document Period End Date     Sep. 30, 2018    
Upfront Rig Mobilizations And Certain Contract Preparation [Member]          
Capitalized Contract Cost [Line Items]          
Capitalized Contract Cost, Net $ 29.0   $ 29.0   $ 40.6
Capitalized Contract Cost, Amortization 10.1 $ 7.1 26.0 $ 21.8  
Deferred Certification Costs          
Capitalized Contract Cost [Line Items]          
Capitalized Contract Cost, Net 13.0   13.0   $ 15.3
Capitalized Contract Cost, Amortization $ 3.3 $ 3.3 $ 9.6 $ 9.1  
Minimum [Member]          
Capitalized Contract Cost [Line Items]          
Remaining duration of drilling contracts 1 month   1 month    
Maximum [Member]          
Capitalized Contract Cost [Line Items]          
Remaining duration of drilling contracts 4 years   4 years