U.S. Pension Plan Investment Allocations by Asset Category (Detail) (USD $) In Thousands, unless otherwise specified	Aug. 31, 2014	Aug. 31, 2013
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of pension plan assets	$ 44,642	$ 34,054
Percentage of fair value of pension plan assets	100.00%	100.00%
Cash and cash equivalents | Level 1 Valuation
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of pension plan assets	0	348
Percentage of fair value of pension plan assets	0.00%	1.00%
Fixed Income Securities | Level 2 Valuation
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of pension plan assets	14,223	12,205
Percentage of fair value of pension plan assets	31.80%	35.90%
Fixed Income Securities | Corporate Bond | Level 2 Valuation
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of pension plan assets	9,749	8,741
Percentage of fair value of pension plan assets	21.80%	25.70%
Fixed Income Securities | Mutual Funds | Level 2 Valuation
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of pension plan assets	4,474	3,464
Percentage of fair value of pension plan assets	10.00%	10.20%
Equity Securities | Mutual Funds | Level 1 Valuation
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of pension plan assets	$ 30,419	$ 21,501
Percentage of fair value of pension plan assets	68.20%	63.10%