Central Merger and Restructuring, Merger and Integration Costs (Tables)

6 Months Ended

Jun. 30, 2017

Business Combinations [Abstract]

Schedule of acquisition related costs

The aggregate costs associated with the restructuring, merger and integration costs are summarized in the following table:

	Three Months Ended				Six Months Ended
(millions) (unaudited)	June 30, 2017		June 30, 2016		June 30, 2017		June 30, 2016
General and administrative expenses	$	1.0	$	0.1	$	1.1	$	0.9
Depreciation and amortization	—		1.4		—		2.4
Total	$	1.0	$	1.5	$	1.1	$	3.3