Commitments and Contingent Liabilities (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Schedule of water cost purchased

Purchased water costs are shown below:

	(Millions of Dollars)
	Years Ended December 31,
Purchased Water	2017		2016		2015
Untreated	$	2.8	$	2.6	$	2.5
Treated		3.3		3.2		3.1
Total Costs	$	6.1	$	5.8	$	5.6

Schedule of future minimum operating lease

The minimum annual future rental commitment under operating leases that have initial or remaining non-cancelable lease terms over the next 5 years and thereafter are as follows:

Year	(Millions of Dollars) Annual Maturities
2018	$ 0.7
2019	$ 0.7
2020	$ 0.7
2021	$ 0.7
2022	$ 0.7
Thereafter	$ 3.8