Accounts Receivable (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Accounts Receivable [Abstract]
Bad debt expense	$ 20.6	$ 20.8	$ 52.9	$ 61.5