Restructuring Costs - Narrative (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | 12 Months Ended | ||||||
|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2020 |
Sep. 30, 2019 |
Sep. 30, 2020 |
Sep. 30, 2019 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2021 |
Dec. 31, 2020 |
|
| Restructuring Cost and Reserve [Line Items] | |||||||||
| Expense | $ 71.7 | $ 4.0 | $ 73.0 | $ 9.4 | $ 20.7 | $ 46.2 | $ 41.6 | ||
| Expected cost remaining | $ 20.7 | $ 46.2 | $ 41.6 | $ 7.9 | |||||
| Multi-Year Restructuring Program | |||||||||
| Restructuring Cost and Reserve [Line Items] | |||||||||
| Expense | 71.1 | ||||||||
| Total expected cost | $ 100.0 | $ 100.0 | |||||||
| Forecast | Multi-Year Restructuring Program | |||||||||
| Restructuring Cost and Reserve [Line Items] | |||||||||
| Expected cost remaining | $ 25.0 | $ 5.0 | |||||||