Revenue (Tables)

9 Months Ended

Sep. 30, 2021

Revenue From Contract With Customer [Abstract]

Schedule of Remaining Performance Obligations

The Company expects to recognize the remaining performance obligations as revenue in future periods as follows:

(millions) (unaudited)	Remaining Performance Obligations
2021	$	17.4
2022		49.5
2023		34.7
2024		20.4
2025		10.1
2026 and thereafter		18.6
Total	$	150.7

Schedule of Contract with Customer, Asset and Liabilities

The following table provides information about accounts receivable, contract assets and contract liabilities with customers and clients as of September 30, 2021 (unaudited) and December 31, 2020:

(millions)	September 30, 2021			December 31, 2020
Accounts receivable	$	115.0		$	102.7
Contract asset		6.3			8.6
Contract liability		(12.5	)		(12.5	)

The following table provides information about changes to contract assets during the nine months ended September 30, 2021 and 2020 (unaudited):

	Nine Months Ended
(millions)	September 30, 2021			September 30, 2020
Balance, beginning of period	$	8.6		$	11.0
Additional contract assets		6.3			6.3
Reclassification to accounts receivable		(8.6	)		(11.0	)
Balance, end of period	$	6.3		$	6.3

The following table provides information about changes to contract liabilities during the nine months ended September 30, 2021 and 2020 (unaudited):

	Nine Months Ended
(millions)	September 30, 2021			September 30, 2020
Balance, beginning of period	$	(12.5	)	$	(19.4	)
Additional contract liabilities		(12.5	)		(8.7	)
Recognition of revenue from contract liabilities		12.5			19.4
Balance, end of period	$	(12.5	)	$	(8.7	)

Schedule of Cost of Contracts Expense

Cost of contracts expense related to service concession arrangements within the scope of Topic 853 and certain management type contracts are recorded as a reduction of revenue.  Cost of contracts expense for the three and nine months ended September 30, 2021 and 2020 (unaudited) was as follows:

	Three Months Ended				Nine Months Ended
(millions)	September 30, 2021		September 30, 2020		September 30, 2021		September 30, 2020
Cost of contracts expense	$	0.3	$	0.2	$	0.8	$	0.6