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Goodwill and Intangible Assets - Additional Information (Details) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Goodwill And Intangible Assets Disclosure [Abstract]        
Amortization expense related to intangible assets $ 1,700,000 $ 2,100,000 $ 5,400,000 $ 6,200,000
Impairments of goodwill or intangible assets     $ 0 $ 0