Fair Value Measurements (Details) (USD $)	3 Months Ended
	Nov. 30, 2011	Aug. 31, 2011	Nov. 30, 2010
Assets and liabilities measured on a recurring and nonrecurring basis [Line Items]
Money market funds (cash and cash equivalents)	$ 1,307,458,000	$ 1,854,927,000
Auction-rate securities (marketable securities)	5,946,000	5,946,000
Total assets at fair value on a recurring basis	1,313,404,000	1,860,873,000
Interest rate swap (other liabilities)	2,588,000	3,363,000
Total liabilities at fair value on a recurring basis	2,588,000	3,363,000
Restructuring obligation	5,211,000
Restructuring obligation - Losses for the three months ended November 30, 2011	(5,562,000)		(3,846,000)
Total liabilities at fair value on a nonrecurring basis	5,211,000
Total liabilities at fair value on a nonrecurring basis, losses	(5,211,000)
Interest rate swap notional amount	40,400,000
Carrying value of debt, excluding capital leases	73,600,000
Lease obligation, net [Member]
Assets and liabilities measured on a recurring and nonrecurring basis [Line Items]
Restructuring obligation - Losses for the three months ended November 30, 2011	(5,211,000)	(17,800,000)	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Assets and liabilities measured on a recurring and nonrecurring basis [Line Items]
Money market funds (cash and cash equivalents)	1,307,458,000	1,854,927,000
Total assets at fair value on a recurring basis	1,307,458,000	1,854,927,000
Significant Other Observable Inputs (Level 2) [Member]
Assets and liabilities measured on a recurring and nonrecurring basis [Line Items]
Total assets at fair value on a recurring basis		0
Interest rate swap (other liabilities)	2,588,000	3,363,000
Total liabilities at fair value on a recurring basis	2,588,000	3,363,000
Significant Unobservable Inputs (Level 3) [Member]
Assets and liabilities measured on a recurring and nonrecurring basis [Line Items]
Auction-rate securities (marketable securities)	5,946,000	5,946,000
Total assets at fair value on a recurring basis	5,946,000	5,946,000
Restructuring obligation	5,211,000
Total liabilities at fair value on a nonrecurring basis	$ 5,211,000