Intangible Assets, net (Tables)

3 Months Ended

Mar. 31, 2018

Intangible Assets, net

Summary of intangible assets, net

		March 31, 2018				December 31, 2017
	Weighted Average	Gross				Gross
	Amortizable	Carrying		Accumulated		Carrying		Accumulated
	Life in Years	Amount		Amortization		Amount		Amortization
		(in millions)
Intangible assets subject to amortization:
Covenants not to compete	4.8	$	0.8	$	(0.4)	$	0.8	$	(0.4)
Customer lists/relationships	14.5		752.6		(402.4)		745.0		(391.3)
Software	10.0		8.1		(8.1)		8.1		(8.1)
Other	5.7		7.6		(6.6)		6.3		(5.9)
			769.1		(417.5)		760.2		(405.7)
Intangible assets not subject to amortization:
Trade names			763.9		—		757.6		—
		$	1,533.0	$	(417.5)	$	1,517.8	$	(405.7)

Summary of estimated aggregate amortization expense

The following is a summary of estimated aggregate amortization expense for the remaining nine months of 2018 and each of the succeeding five years:

	(in millions)
2018 (remaining nine months)	$	35.7
2019		47.5
2020		47.5
2021		43.4
2022		35.2
2023		29.1