Significant Accounting Policies - Revenue Recognition (Details)	12 Months Ended
	Dec. 31, 2021 yr
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
RUPO maintenance contracts, number of additional years recognized	3
Contract assets, incurred costs, billing and collection, period	1 year
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Customer payments on engineering and construction contracts, period until due	30 days
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Customer payments on engineering and construction contracts, period until due	45 days