Revenue - Change in Contract Assets and Liabilities (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)
Contract assets
Accounts receivable, net of allowances, beginning	$ 200.8
Change in accounts receivable	35.5
Accounts receivable, net of allowances, ending	236.3
Unbilled contract revenue, beginning	79.4
Change in unbilled contract revenue	14.1
Unbilled contract revenue, ending	$ 93.5
Change in accounts receivable (as a percentage)	17.70%
Change in unbilled contract revenue (as a percentage)	17.80%
Contract liabilities
Customer advances and billings in excess of contract revenue, beginning	$ 118.9
Change in customer advances and billings in excess of contract revenue	29.6
Customer advances and billings in excess of contract revenue, ending	148.5
Long term deferred revenue, beginning	1.9
Change in long-term deferred revenue	(1.5)
Long-term deferred revenue, ending	$ 0.4
Change in customer advances and billings in excess of contract revenue (as a percentage)	24.90%
Change in long-term deferred revenue (as a percentage)	(78.90%)