Unaudited Condensed Consolidated Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2014
Net change in unrealized gains on available-for-sale securities, net tax provision (benefit)	$ 0.0	$ 0.0	$ 0.0
Net unrealized gains on cash flow hedges, net tax provision	9.1	29.2
Postretirement plans and workers' compensation obligations, net tax provision	$ 2.5	$ 2.1