Other Liabilities - Performance Obligations (Details) $ in Millions	Dec. 31, 2020 USD ($)
Other Liabilities
Remaining performance obligations	$ 10.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Other Liabilities
Remaining performance obligations	$ 2.6
Performance obligations
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Other Liabilities
Remaining performance obligations	$ 4.5
Performance obligations
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Other Liabilities
Remaining performance obligations	$ 3.0
Performance obligations
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Other Liabilities
Remaining performance obligations	$ 0.6
Performance obligations
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period