Revenues, net - Contracts with Customer, Receivables, Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Accounts receivable, net	$ 157,505	$ 171,864	$ 171,864
Contract assets	5,074		5,391
Contract liabilities
Deferred revenue (consideration received in advance)	14,739		11,259
Consideration received for process transition activities	$ 2,579		$ 3,036