Other Intangible Assets, net

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Other Intangible Assets, net

Other Intangible Assets, net

The following presents a summary of other intangible assets:

		December 31,
		2017							2016
(millions)	Weighted Average Life (Years)	Acquired Intangible Assets, Gross (1)		Accumulated Amortization			Acquired Intangible Assets, Net		Acquired Intangible Assets, Gross(1)		Accumulated Amortization			Acquired Intangible Assets, Net
Covenant not to compete	1.0	$	0.9	$	(0.9	)	$	—	$	0.9	$	(0.9	)	$	—
Trade names and trademarks	1.5	9.8		(9.7		)	0.1		9.8		(9.6		)	0.2
Proprietary know how	1.5	34.6		(34.5		)	0.1		34.7		(32.6		)	2.1
Management contract rights	10.9	81.0		(27.1		)	53.9		81.0		(22.0		)	59.0
Acquired intangible assets, net (2)	10.9	$	126.3	$	(72.2	)	$	54.1	$	126.4	$	(65.1	)	$	61.3

(1) Excludes the original cost and accumulated amortization on fully amortized intangible assets.

(2) Intangible assets have estimated remaining lives between one and 14 years.

The table below shows the amortization expense related to intangible assets for the years ended December 31, 2017, 2016 and 2015, and is included in Depreciation and amortization within the Consolidated Statements of Income.

	Year Ended December 31,
(millions)	2017		2016		2015
Amortization expense	$	7.2	$	14.6	$	15.1

The expected future amortization of intangible assets as of December 31, 2017 is as follows:

(millions)	Intangible asset amortization
2018	$	5.3
2019	5.2
2020	5.2
2021	5.2
2022	5.1
2023 and Thereafter	28.1
Total	$	54.1