MATERIALS, SUPPLIES, AND INVENTORIES (Tables)

3 Months Ended

Mar. 31, 2018

Inventory Disclosure [Abstract]

Schedule of inventory

Our inventory consisted of:

(in millions)	March 31, 2018		December 31, 2017
Natural gas in storage	$	34.8	$	209.0
Materials and supplies	213.7		211.2
Fossil fuel	127.5		118.8
Total	$	376.0	$	539.0