Contracts with Customers (Tables)

9 Months Ended

Sep. 30, 2021

Revenue From Contract With Customer [Abstract]

Summary of Unbilled Receivables, Contract Assets and Contract Liabilities from Contracts with Customers

Information about unbilled receivables, contract assets and contract liabilities from contracts with customers is as follows (in millions):

	September 30 2021		December 31, 2020
Unbilled receivables	$	810.6	$	603.1
Deferred contract costs		76.3		102.0
Deferred revenue		588.2		541.3

Summary of Changes in Deferred Revenue Balances

Significant changes in the deferred revenue balances, which include foreign currency translation adjustments, during the period are as follows (in millions):

				Risk
	Brokerage			Management			Total
Deferred revenue at December 31, 2020	$	354.7		$	186.6		$	541.3
Incremental deferred revenue		283.3			77.4			360.7
Revenue recognized during the nine-month period ended September 30, 2021 included in deferred revenue at December 31, 2020		(256.5	)		(76.8	)		(333.3	)
Net change in collected billings/deposits received from customers		1.5			7.3			8.8
Impact of change in foreign exchange rates		1.0			—			1.0
Deferred revenue recognized from business acquisitions		9.7			—			9.7
Deferred revenue at September 30, 2021	$	393.7		$	194.5		$	588.2

Summary of Expected Revenue Related to Performance Obligations

The estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied (or partially unsatisfied) at the end of the reporting period is as follows (in millions):

	Brokerage		Risk Management		Total
2021 (remaining three months)	$	235.6	$	89.4	$	325.0
2022		135.8		54.6		190.4
2023		19.3		23.4		42.7
2024		1.5		10.6		12.1
2025		0.8		5.9		6.7
Thereafter		0.7		10.6		11.3
Total	$	393.7	$	194.5	$	588.2