Short-term Borrowings and Current Portion of Long-term Debt (Narrative) (Details) (USD $)						0 Months Ended
	Sep. 30, 2014	Apr. 30, 2013	Sep. 30, 2014 Revolving credit facility [Member]	Sep. 30, 2014 Commercial paper program and letters of credit [Member]	Sep. 30, 2014 Committed letters of credit [Member]	Apr. 10, 2014 364-day term loan facility [Member]	May 02, 2013 364-day term loan facility [Member]	Sep. 30, 2014 Domestic and foreign facility [Member]	Sep. 30, 2014 Uncommitted letters of credit [Member]	Sep. 30, 2014 Maximum [Member] Revolving credit facility [Member]	Sep. 30, 2014 Bi-Lateral Revolver Debt [Member] Domestic and foreign facility [Member]	Sep. 30, 2014 London Interbank Offered Rate (LIBOR) [Member] Domestic and foreign facility [Member]
Short-term Debt [Line Items]
Credit agreement, maximum capacity		$ 300,000,000	$ 2,250,000,000	$ 2,250,000,000		$ 400,000,000
Ratio of indebtedness to net capital percent required										0.6
Letters of credit outstanding, amount					32,000,000				584,000,000
Debt instrument, term						364 days	364 days
Short term borrowings								272,000,000			180,000,000
Interest rate at period end												1.35%
Performance bonds	$ 277,000,000