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Summary of Significant Accounting Policies - Research and Engineering (Details) - In Process Research and Development - Two T D Drilling - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Intangible Assets      
Intangible Assets $ 32.5 $ 21.7  
Transfer of research and development expenses to completed technology $ 0.0 $ 0.0 $ 0.0