Debt (Details) (USD $)	3 Months Ended	6 Months Ended
	Nov. 30, 2013	Feb. 28, 2014	Aug. 31, 2013
Debt [Line Items]
Total debt		$ 74,423,000	$ 692,054,000
Less short-term borrowings and current portion of long-term debt		(30,781,000)	(628,050,000)
Long-term debt		43,642,000	64,004,000
Letters of credit outstanding		24,000,000	14,000,000
Bank Facility [Member]
Debt [Line Items]
Total debt		0	605,000,000
Borrowing capacity		625,000,000
Debt term		5 years
Debt repaid	605,000,000
Weighted average interest rate			3.50%
Bank Facility [Member] | Minimum [Member]
Debt [Line Items]
Fees		0.25%
Bank Facility [Member] | Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt [Line Items]
Fees for borrowings		1.25%
Bank Facility [Member] | Maximum [Member]
Debt [Line Items]
Fees		0.40%
Bank Facility [Member] | Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt [Line Items]
Fees for borrowings		1.85%
Capital Lease Obligations [Member]
Debt [Line Items]
Total debt		38,752,000	49,628,000
Other Debt [Member]
Debt [Line Items]
Total debt		$ 35,671,000	$ 37,426,000
Weighted average interest rate		5.80%	5.30%
Technology Purchase Obligation [Member]
Debt [Line Items]
Debt term		10 years