Consolidated Statement of Comprehensive Income Parentheticals - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Unrealized Gain (Loss) on Securities, Income Tax Expense (Benefit)	$ 0.2	$ (0.4)	$ 0.2	$ (0.3)
Unrealized Gain on Derivatives, Income Tax Expense	0.0	0.0	0.0	0.1
Defined Benefit Pension and Other Postretirement Benefit Plans, Income Tax Expense	$ 0.1	$ 0.3	$ 0.3	$ 0.7