Lines of Credit and Financing Arrangements (Details Textual 1) (USD $)	12 Months Ended					12 Months Ended
	Dec. 31, 2013	Oct. 31, 2013	Dec. 31, 2012	Nov. 30, 2013 Minimum [Member]	Nov. 30, 2013 Maximum [Member]	Dec. 31, 2013 Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum securitization, amount		$ 160,000,000		$ 160,000,000	$ 220,000,000
Maximum securitization as percentage of net pool balance	100.00%
Program fee	0.60%
Average floating commercial paper rate	0.78%		0.85%
Unused fee	101.00%
Fixed rate of agreement	0.30%
Domestic Revolving Credit Facility						650,000,000
Borrowings under Domestic Revolving Credit Facility						17,000,000
Committed standby letters of credit						59,500,000
Available for future borrowings						599,500,000
Extended maturity date						Oct. 31, 2016
Maximum increase in borrowings under Domestic Revolving Credit Facility						$ 100,000,000