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Revenue Recognition, Contracts with Customers - Narrative (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Revenue from Contract with Customer [Abstract]      
Revenue recognized from performance obligation satisfied in previous periods $ 4.5 $ 5.0 $ 5.6
Revenue recognized that was included in contract liability at beginning of period $ 14.0 $ 5.6 $ 4.9