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Revenue - Additional Information (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Revenue from Contract with Customer [Abstract]        
Contract with Customer, Liability, Revenue Recognized $ 3,377 $ 3,740 $ 10,870 $ 8,984
Period in Which Performance Obligations Under Client Arrangements Settled     1 year