MATERIALS, SUPPLIES, AND INVENTORIES (Tables)

6 Months Ended

Jun. 30, 2017

Inventory Disclosure [Abstract]

Schedule of inventory

Our inventory consisted of:

(in millions)	June 30, 2017		December 31, 2016
Materials and supplies	$	153.2	$	148.1
Fossil fuel	100.1		91.1
Natural gas in storage	24.9		31.8
Total	$	278.2	$	271.0