Summary of Significant Accounting Policies (Sale of Receivables) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accounting Policies [Abstract]
Proceeds from sale of other receivables	$ 6.6	$ 28.9	$ 39.7	$ 61.0