Reconciliation Between Effective and Statutory Tax Rates on Continuing Operations (Detail)	12 Months Ended
Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Income Taxes [Line Items]
Federal statutory rate	35.00%	35.00%	35.00%
State income taxes, net of federal benefit	0.10%	0.70%	1.00%
Impact of foreign operations	(3.40%)	0.10%	(0.50%)
Change in valuation allowance			(0.10%)
Noncontrolling interest in flow-through entity	(6.00%)	(7.40%)	(5.70%)
Permanent differences and other	1.40%		0.20%
Effective tax rate	27.10%	28.40%	29.90%

Effective Income Tax Rate Reconciliation Permanent And Other Differences

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Income Taxes [Line Items]

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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-Publisher FASB
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to statutory income tax expense (benefit) outside of the country of domicile.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to noncontrolling interest income (loss) exempt from income taxes.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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