Revenue (Tables)

6 Months Ended

Jun. 30, 2020

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
2020	$	24.0
2021		35.8
2022		20.4
2023		13.0
2024		7.2
2025 and thereafter		7.0
Total	$	107.4

Schedule of Contract with Customer, Asset and Liability

The following table provides information about accounts receivable, contract assets and contract liabilities with customers and clients as of June 30, 2020 (unaudited) and December 31, 2019:

(millions)	June 30, 2020			December 31, 2019
Accounts receivable	$	93.3		$	151.3
Contract asset		7.0			11.0
Contract liability		(11.3	)		(19.4	)

The following table provides information about changes to contract asset balances during the six months ended June 30, 2020 and 2019:

	Six Months Ended
(millions) (unaudited)	June 30, 2020			June 30, 2019
Balance, beginning of period	$	11.0		$	11.4
Additional contract assets		7.0			11.8
Reclassification to accounts receivable		(11.0	)		(11.4	)
Balance, end of period	$	7.0		$	11.8

The following table provides information about changes to contract liability balances during the six months ended June 30, 2020 and 2019:

	Six Months Ended
(millions) (unaudited)	June 30, 2020			June 30, 2019
Balance, beginning of period	$	(19.4	)	$	(19.1	)
Additional contract liabilities		(11.3	)		(14.9	)
Recognition of revenue from contract liabilities		19.4			19.1
Balance, end of period	$	(11.3	)	$	(14.9	)

Schedule of Amortization Expense Related to Cost of Contracts

Amortization expense of cost of contracts related to service concession arrangements within the scope of Topic 853 and certain management type contracts are recorded as a reduction of revenue and were not significant for the three and six months ended June 30, 2020 and 2019, respectively.  Amortization expense related to cost of contracts for the three and six months ended June 30, 2020 and 2019 was as follows:

	Three Months Ended				Six Months Ended
(millions) (unaudited)	June 30, 2020		June 30, 2019		June 30, 2020		June 30, 2019
Amortization expense	$	0.3	$	0.3	$	0.7	$	0.6