Summary of Significant Accounting Policies (Sale of Receivables) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accounting Policies [Abstract]
Proceeds from sale of other receivables	$ 9.4	$ 37.7	$ 49.1	$ 98.7