Revenue Contract Balances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Accounts receivable, net of allowance of $68.5 and $98.3, respectively	$ 5,316.0	$ 5,177.7
Accounts receivable, billable to clients	2,023.0	2,347.2
Contract with Customer, Asset, after Allowance for Credit Loss	67.4	62.3
Contract liabilities	680.0	688.5
Revenue, remaining performance obligation, amount	780.3
Net revenue	$ 9,449.4	$ 9,107.9