Revenue from Contracts with Customer (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Remaining performance obligation	$ 7,600,000		$ 7,600,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract liabilities	10,100,000		10,100,000		$ 7,200,000
Contract liability , revenue recognized	1,800,000		4,300,000
Lease income	$ 1,000,000.0	$ 0	$ 2,700,000	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation, percentage	34.00%		34.00%
Remaining performance obligation, period	12 months		12 months