Contracts in Progress - Remaining Performance Obligation (Details) $ in Millions	6 Months Ended
	Jun. 30, 2021 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Performance obligations expected to be satisfied	$ 394.4
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Performance obligations expected to be satisfied	$ 374.8
Performance obligations expected to be satisfied, percentage	95.00%
Performance obligations expected to be satisfied, expected timing	12 months