Inventories (Tables)

9 Months Ended

Sep. 30, 2015

Inventory Disclosure [Abstract]

Schedule of Inventory, Current [Table Text Block]

Our inventory consisted of:

(in millions)	September 30, 2015		December 31, 2014
Materials, supplies, and inventories
Natural gas in storage	$	310.3	$	124.8
Materials and supplies	226.7		150.2
Fossil fuel	182.8		125.6
Total	$	719.8	$	400.6