Goodwill and Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of Changes in Carrying Value

The following table represents our change in carrying value of intangible assets (in millions):

	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Three Months Ended March 31, 2017
Customer relationships, beginning of period	$	1,795.8	$	(171.6	)	$	1,624.2
Amortization expense	—		(29.5		)	(29.5		)
Customer relationships, end of period	$	1,795.8	$	(201.1	)	$	1,594.7

Schedule of Amortization Expense

The following table summarizes our estimated aggregate amortization expense for the next five years (in millions):

2017 (remaining)	$	88.4
2018	117.9
2019	117.9
2020	117.9
2021	117.9
Thereafter	1,034.7
Total	$	1,594.7