Income Taxes (Details) (USD $)	12 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2012
Geographical sources of income from continuing operations [Abstract]
United States	$ 384,146,000	$ 468,738,000	$ 727,965,000
Foreign	(51,406,000)	(38,771,000)	(61,679,000)
Income from continuing operations before income taxes	332,740,000	429,967,000	666,286,000
Current:
U.S. Federal	(114,997,000)	(174,020,000)	(212,113,000)
State and local	(17,664,000)	(30,250,000)	(46,676,000)
Foreign	(2,575,000)	(1,704,000)	(2,140,000)
Total current	(135,236,000)	(205,974,000)	(260,929,000)
Deferred:
U.S. Federal	(3,154,000)	20,420,000	(28,999,000)
State and local	240,000	3,132,000	(1,039,000)
Foreign	16,826,000	5,965,000	8,188,000
Total deferred	13,912,000	29,517,000	(21,850,000)
Provision for income taxes	(121,324,000)	(176,457,000)	(282,779,000)
Effective income tax rate reconciliation [Abstract]
Statutory U.S. federal income tax rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	4.80%	4.30%	4.20%
Foreign taxes	0.90%	2.20%	1.40%
Goodwill impairments	0.00%	0.00%	0.90%
Internal Revenue Service settlement	(3.10%)	0.00%	0.00%
Mexico tax reform	(0.80%)	0.00%	0.00%
Contingent consideration	1.00%	0.00%	0.00%
Other, net	(1.30%)	(0.50%)	0.90%
Effective income tax rate	36.50%	41.00%	42.40%
Deferred tax assets:
Allowance for doubtful accounts	13,100,000	16,479,000
Leasing transactions	74,528,000	86,946,000
Net operating loss carry-forward	16,938,000	25,055,000
Share-based compensation	23,796,000	35,123,000
Deferred revenue	18,539,000	4,698,000
Other	62,436,000	47,231,000
Gross deferred tax assets	209,337,000	215,532,000
Valuation allowance	(21,048,000)	(17,998,000)
Deferred tax assets, net of valuation allowance	188,289,000	197,534,000
Deferred tax liabilities:
Fixed assets	36,149,000	42,485,000
Intangibles	47,344,000	35,109,000
Other	6,264,000	7,929,000
Gross deferred tax liabilities	89,757,000	85,523,000
Net deferred income taxes	98,532,000	112,011,000
Net operating loss carry-forwards [Line Items]
Income Tax Expense (Benefit)	121,324,000	176,457,000	282,779,000
Unrecognized tax benefits rollforward [Abstract]
Beginning balance	44,057,000	32,207,000	25,811,000
Additions based on tax positions taken in the current year	0	13,095,000	7,708,000
Additions for tax positions taken in prior years	2,214,000	5,953,000	813,000
Settlement with tax authorities	(7,184,000)	(197,000)	(733,000)
Reductions for tax positions of prior years	(10,541,000)	(2,635,000)	0
Reductions due to lapse of applicable statute of limitations	(10,148,000)	(4,366,000)	(1,392,000)
Ending balance	18,398,000	44,057,000	32,207,000
Uncertain tax position interest and penalties expense	1,900,000	(100,000)	(400,000)
Uncertain tax position interest and penalties accrued	2,200,000	4,200,000
Reasonably possible change in unrecognized tax benefits	13,800,000
Unrecognized tax benefits that would impact tax rate	10,000,000
United States [Member]
Net operating loss carry-forwards [Line Items]
Net operating loss carry-forwards	23,200,000
Foreign [Member]
Net operating loss carry-forwards [Line Items]
Net operating loss carry-forwards	59,600,000
Internal Revenue Service (IRS) [Member]
Deferred:
Provision for income taxes	10,200,000
Net operating loss carry-forwards [Line Items]
Income Tax Expense (Benefit)	$ (10,200,000)