XML 25 R14.htm IDEA: XBRL DOCUMENT v3.19.2
MATERIALS, SUPPLIES, AND INVENTORIES
 6 Months Ended
Jun. 30, 2019
Inventory Disclosure [Abstract]  
MATERIALS, SUPPLIES, AND INVENTORIES MATERIALS, SUPPLIES, AND INVENTORIES

Our inventory consisted of:
(in millions)
 
June 30, 2019
 
December 31, 2018
Materials and supplies
 
$
52.3

 
$
48.9

Fossil fuel
 
34.9

 
29.2

Natural gas in storage
 
18.3

 
24.9

Total
 
$
105.5

 
$
103.0



Substantially all materials and supplies, fossil fuel, and natural gas in storage inventories are recorded using the weighted-average cost method of accounting.