Property and Equipment (Summary Of Property And Equipment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total	$ 72,677	$ 65,133
Less accumulated depreciation	(41,268)	(36,843)
Property and equipment, net	31,409	28,290
Generators and related equipment
Property, Plant and Equipment [Line Items]
Total	$ 20,175	18,669
Building under finance lease
Property, Plant and Equipment [Line Items]
Estimated Useful Life	15 years
Total	$ 14,250	14,250
Computer, software and office equipment
Property, Plant and Equipment [Line Items]
Total	7,762	8,045
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total	8,501	6,697
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total	5,877	5,849
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total	8,727	8,645
Construction in progress
Property, Plant and Equipment [Line Items]
Total	5,999	2,067
Land
Property, Plant and Equipment [Line Items]
Total	1,006	502
Equipment under finance leases
Property, Plant and Equipment [Line Items]
Total	$ 380	$ 409
Minimum | Generators and related equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life	1 year
Minimum | Computer, software and office equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Minimum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Minimum | Furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Minimum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Minimum | Equipment under finance leases
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Maximum | Generators and related equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Maximum | Computer, software and office equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Maximum | Machinery and equipment
Property, Plant and Equipment [Line Items]
Estimated Useful Life	7 years
Maximum | Furniture and fixtures
Property, Plant and Equipment [Line Items]
Estimated Useful Life	7 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated Useful Life	15 years
Maximum | Equipment under finance leases
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years