Accounting Standards and Significant Accounting Policies (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle
Accounts receivable, net	$ 515.9	$ 535.0
Allowance for losses	14.0	12.1
Unbilled Revenues
New Accounting Pronouncements or Change in Accounting Principle
Accounts receivable, net	129.5	140.3
Unbilled Revenues | Retention Receivable
New Accounting Pronouncements or Change in Accounting Principle
Accounts receivable, net	$ 8.0	$ 7.7