Commitments and Contingent Liabilities (Tables)

12 Months Ended

Dec. 31, 2016

Commitments and Contingencies Disclosure [Abstract]

Schedule of water cost purchased

	(Millions of Dollars)
	Years Ended December 31,
Purchased Water	2016		2015		2014
Untreated	$	2.6	$	2.5	$	2.4
Treated		3.2		3.1		3.1
Total Costs	$	5.8	$	5.6	$	5.5