Summary of Significant Accounting Policies - Accounts Receivable, Contract Assets and Contract Liabilities - Performance Obligation (Details) $ in Millions	Dec. 31, 2020 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Performance obligation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Estimated revenue to be recognized	$ 6.8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Performance obligation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Estimated revenue to be recognized	$ 3.5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Performance obligation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Estimated revenue to be recognized	$ 3.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Performance obligation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	0 months
Estimated revenue to be recognized	$ 4.3