Accounts Receivable (Tables)

9 Months Ended

Sep. 30, 2013

Accounts Receivable, Net, Current [Abstract]

Schedule of Accounts Receivable

	September 30, 2013		December 31, 2012
	(millions)
Utility customers	$	121.3	$	118.3
DOE pro-rata share of RD&D program funding	24.8		4.4
Contract services, primarily DOE:
Billed revenue	9.7		10.5
Unbilled revenue	2.9		1.6
	12.6		12.1
Current accounts receivable, net	$	158.7	$	134.8