Income Taxes (Tables)

9 Months Ended

Sep. 30, 2015

Income Tax Disclosure [Abstract]

Reconciliation of Unrecognized Tax Benefits

A reconciliation of the amount of unrecognized tax benefit is as follows:

(Millions of Dollars)	Sept. 30, 2015		Dec. 31, 2014
Unrecognized tax benefit — Permanent tax positions	$	1.6	$	1.5
Unrecognized tax benefit — Temporary tax positions	12.7		11.7
Total unrecognized tax benefit	$	14.3	$	13.2

Tax Benefits Associated with NOL and Tax Credit Carryforwards

The unrecognized tax benefit amounts were reduced by the tax benefits associated with net operating loss (NOL) and tax credit carryforwards. The amounts of tax benefits associated with NOL and tax credit carryforwards are as follows:

(Millions of Dollars)	Sept. 30, 2015			Dec. 31, 2014
NOL and tax credit carryforwards	$	(6.3	)	$	(4.8	)