Goodwill (Tables)

9 Months Ended

Sep. 30, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Amounts for Goodwill and Changes to Carrying Value by Operating Segment

The amounts for goodwill and changes to carrying value by reportable segment are as follows:

(millions) (unaudited)	Region One			Region Two		Total
Balance as of December 31, 2017	$	369.0		$	62.7	$	431.7
Foreign currency translation	(0.1		)	—		(0.1		)
Balance as of September 30, 2018	$	368.9		$	62.7	$	431.6