Accounts Receivable, Net of Allowance (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2014 USD ($)
Financing Receivable, Non-Recourse Arrangement [Member]
Schedule of Accounts Receivable, Net of Allowance [Line Items]
Increase (decrease) in cash collections from non-recourse financing arrangement	$ 70.0
Uncollectible Receivables [Member]
Schedule of Accounts Receivable, Net of Allowance [Line Items]
Change in estimate, provision for doubtful accounts	$ 0.5