Intangible Assets, net (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Intangible assets subject to amortization:
Intangible assets subject to amortization, Gross Carrying Amount	$ 708.2	$ 708.2		$ 760.2
Intangible assets subject to amortization, Accumulated Amortization	(394.1)	(394.1)		(405.7)
Intangible assets
Intangible assets, Gross Carrying Amount	1,458.6	1,458.6		1,517.8
Amortization expense for intangible assets		35.1	$ 38.9
Changes in intangible assets due to foreign currency translation losses		1.5
Summary of estimated aggregate amortization expense for each of the succeeding five years
2018 (remaining three months)	10.5	10.5
2019	41.9	41.9
2020	41.9	41.9
2021	40.2	40.2
2022	35.5	35.5
2023	29.5	29.5
KMS and DuBose
Intangible assets
Intangible assets, Gross Carrying Amount	22.9	22.9
Trade names
Intangible assets not subject to amortization:
Intangible assets not subject to amortization, Gross Carrying Amount	750.4	750.4		757.6
Intangible assets
Impairment losses of intangible assets, indefinite-lived	16.5	16.5
Trade names | KMS and DuBose
Intangible assets not subject to amortization:
Intangible assets not subject to amortization, Gross Carrying Amount	10.0	$ 10.0
Covenants not to compete
Intangible assets subject to amortization:
Weighted average amortizable life in years		4 years 8 months 12 days
Intangible assets subject to amortization, Gross Carrying Amount	0.9	$ 0.9		0.8
Intangible assets subject to amortization, Accumulated Amortization	(0.5)	$ (0.5)		(0.4)
Customer lists/relationships
Intangible assets subject to amortization:
Weighted average amortizable life in years		15 years 1 month 6 days
Intangible assets subject to amortization, Gross Carrying Amount	698.2	$ 698.2		745.0
Intangible assets subject to amortization, Accumulated Amortization	(384.6)	(384.6)		(391.3)
Intangible assets
Impairment losses of intangible assets, finite-lived	16.7	$ 16.7
Software
Intangible assets subject to amortization:
Weighted average amortizable life in years		10 years
Intangible assets subject to amortization, Gross Carrying Amount	8.1	$ 8.1		8.1
Intangible assets subject to amortization, Accumulated Amortization	(8.1)	$ (8.1)		(8.1)
Other
Intangible assets subject to amortization:
Weighted average amortizable life in years		7 years 7 months 6 days
Intangible assets subject to amortization, Gross Carrying Amount	1.0	$ 1.0		6.3
Intangible assets subject to amortization, Accumulated Amortization	$ (0.9)	$ (0.9)		$ (5.9)