Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Intangible Assets

Other Intangible Assets

A summary of our identifiable intangible assets are as follows (in millions):

As of December 31, 2017	Useful Life	Gross		Accumulated Amortization			Net
Intangible Assets subject to amortization:
Supply contract	11.5 years	12.2		$	(12.2	)	$	—
Third-party fuel supply agreement	10 years	49.0		(2.4		)	46.6
Capacity contract	8 years	9.3		(9.2		)	0.1
Fuel trade name	8.7 years	4.0		(0.4		)	3.6
Below market leases	13 - 15 years	0.6		(0.1		)	0.5
Intangible assets not subject to amortization:
Rights-of-way	Indefinite	30.1					30.1
Line space history	Indefinite	9.6					9.6
Liquor licenses	Indefinite	8.5					8.5
Refinery permits	Indefinite	2.1					2.1
Total		$	125.4	$	(24.3	)	$	101.1

As of December 31, 2016	Useful Life	Gross		Accumulated Amortization			Net
Intangible Assets subject to amortization:
Supply contract	11.5 years	$	12.2	$	(11.0	)	$	1.2
Capacity contract	8 years	9.3		(9.0		)	0.3
Intangible assets not subject to amortization:
Rights-of-way	Indefinite	17.3					17.3
Line space history	Indefinite	7.9					7.9
Total		$	46.7	$	(20.0	)	$	26.7

Schedule of Amortization Expense

Amortization expense for the next five years is estimated to be as follows:

2018	$	6.1
2019	6.0
2020	6.0
2021	6.0
2022	5.6