Revenue (Change in Deferred Commissions) (Details) $ in Millions |
12 Months Ended |
---|---|
Dec. 31, 2019
USD ($)
| |
Revenue from Contract with Customer [Abstract] | |
Balance as of January 1, 2019 | $ 25.1 |
Commissions earned and capitalized | 24.9 |
Amortization of capitalized amounts | (19.6) |
Balance as of December 31, 2019 | $ 30.4 |