Intangible Assets (Tables)

6 Months Ended

Jun. 30, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Intangible Assets

The following table provides the gross carrying value and accumulated amortization for each major class of intangible asset at June 30, 2019 and December 31, 2018 (in millions, except weighted average useful life):

		June 30, 2019							December 31, 2018
	Weighted Average Useful Life	Gross Carrying Value		Accumulated Amortization			Net Book Value		Gross Carrying Value		Accumulated Amortization			Net Book Value
Customer relationships	17 years	$	160.9	$	(10.9	)	$	150.0	$	160.9	$	(6.1	)	$	154.8
Tradename	1 year	—		—			—		1.1		(1.1		)	—
Technology	6 years	26.8		(5.1		)	21.7		26.8		(2.9		)	23.9
Favorable leasehold interests	1-8 years	—		—			—		2.3		(0.5		)	1.8
Total intangible assets		$	187.7	$	(16.0	)	$	171.7	$	191.1	$	(10.6	)	$	180.5

Schedule of Estimated Annual Amortization Expense

Estimated annual amortization expense related to intangible assets with definite lives as of June 30, 2019 is as follows (in millions):

Remainder of 2019	$	7.0
2020	13.9
2021	13.9
2022	13.9
2023	13.9
Thereafter	109.1
Total	$	171.7