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Revenue Information - Narrative (Details)
3 Months Ended 6 Months Ended
Jun. 30, 2021
USD ($)
revenueStream
Jun. 30, 2020
USD ($)
Jun. 30, 2021
USD ($)
revenueStream
Jun. 30, 2020
USD ($)
Dec. 31, 2020
USD ($)
Revenue from Contract with Customer [Abstract]          
Number of revenue streams | revenueStream 2   2    
Revenue that was included in deferred revenue balances $ 15,500,000 $ 14,400,000 $ 11,400,000 $ 13,900,000  
Contract assets 0   0   $ 0
Revenue recognized from performance obligations satisfied in previous periods $ 0 $ 0 $ 0 $ 0