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Goodwill and Intangible Assets - Additional Information (Details) - USD ($)
$ in Millions
8 Months Ended 12 Months Ended
Dec. 31, 2015
Dec. 31, 2017
Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]      
Amortization $ 2.6 $ 18.3 $ 6.1
Estimated amortization expense for 2018   25.1  
Estimated amortization expense for 2019   24.4  
Estimated amortization expense for 2020   23.9  
Estimated amortization expense for 2021   23.5  
Estimated amortization expense for 2022   $ 23.0