Revenue - Contract Estimates (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Revenue from Contract with Customer [Abstract] | |||
| Gross favorable adjustment to operating income | $ 3.1 | $ 1.6 | $ 11.6 |
| Net favorable adjustment to operating income | $ (4.4) | $ (0.8) | $ (9.7) |