Debt (Receivables Facility) (Narrative) (Details) (USD $)	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Securitized accounts receivable	$ 555,600,000	$ 556,500,000
Short-term borrowings	405,396,000	298,987,000
Receivables Facility
Debt Instrument [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
Short-term borrowings	$ 235,000,000	$ 180,000,000
Interest rate on borrowings	0.96%