CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net income	$ 36.0	$ 25.2
Pension Plan and Restoration of Retirement Income Plan:
Amortization of deferred net loss, net of tax of $0.4 and $0.4, respectively	0.6	0.8
Postretirement Benefit Plans:
Amortization of prior service cost, net of tax of ($0.0) and ($0.2), respectively	0.0	(0.4)
Other comprehensive income, net of tax	0.6	0.4
Comprehensive income	$ 36.6	$ 25.6