Derivative Instruments (Tables)

12 Months Ended

Dec. 31, 2017

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Fair values for derivatives

The fair values, balance sheet presentation, and the hedge designation status of derivative instruments at December 31, 2017 and 2016 are presented in the table below: 

		Fair Value (Level 2) as of
(in millions)	Balance Sheet Location	December 31, 2017		December 31, 2016
Asset Derivatives
Interest rate swaps — designated as hedge	Deferred charges and other assets	$	—	$	1.3
Liability Derivatives
Interest rate swaps — designated as hedge	Other liabilities and deferred credits	0.6		—

Income statement impact of derivative instruments not designated as hedging instruments

The income statement impact of derivatives are presented in the table below:

		Amount of Gain (Loss) Recognized in Income on Derivatives
(in millions)	Income Statement Location	2017			2016			2015
Designated as hedges
Interest rate swaps	Interest expense	$	3.2		$	4.7		$	7.2
Not designated as hedges
Forward exchange contracts	Other operating income	(0.8		)	(0.8		)	0.7
Total		$	2.4		$	3.9		$	7.9