Debt (Receivables Facility) (Narrative) (Details) (USD $)					9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 Receivables Facility	Dec. 31, 2012 Receivables Facility	Sep. 30, 2013 Receivables Facility
Short-term Debt [Line Items]
Accounts receivable securitization facility maximum borrowing capacity			$ 400,000,000
Debt instrument, basis spread on variable rate					0.75%
Commitment fee percentage					35 basis points
Securitized accounts receivable	629,800,000	556,500,000
Short-term borrowings	$ 522,636,000	$ 298,987,000	$ 337,000,000	$ 180,000,000
Interest rate on borrowings			0.95%