Revolving Notes - Additional Information (Detail) (USD $)	3 Months Ended
	Nov. 30, 2014	Aug. 31, 2014
Line of Credit Facility [Line Items]
Line of credit facility outstanding amount	$ 46,527,000	$ 13,081,000
Senior Secured Credit Facility Revolving Line Of Credit
Line of Credit Facility [Line Items]
Number of senior secured credit facilities	3
Line of credit facility maximum capacity	358,200,000
North American Revolving Credit Facility
Line of Credit Facility [Line Items]
Letter of credit facility outstanding amount	8,600,000	9,600,000
Line of credit facility outstanding amount	15,000,000
North American Revolving Credit Facility | Senior Secured Credit Facility Revolving Line Of Credit
Line of Credit Facility [Line Items]
Line of credit facility maximum capacity	290,000,000
Line of credit maturity date	2016-06
North American Revolving Credit Facility | Senior Secured Credit Facility Revolving Line Of Credit | LIBOR
Line of Credit Facility [Line Items]
Debt instrument, percentage points added to the reference rate	2.25%
North American Revolving Credit Facility | Senior Secured Credit Facility Revolving Line Of Credit | Prime Rate
Line of Credit Facility [Line Items]
Debt instrument, percentage points added to the reference rate	1.25%
Mexican Joint Venture Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility outstanding amount	31,500,000	13,100,000
Mexican Joint Venture Credit Facility | Senior Secured Credit Facility Revolving Line Of Credit
Line of Credit Facility [Line Items]
Line of credit facility maximum capacity	50,000,000
Number of lines of credits	2
Mexican Joint Venture Credit Facility | Senior Secured Credit Facility Revolving Line Of Credit | First Line of Credit
Line of Credit Facility [Line Items]
Line of credit facility maximum capacity	20,000,000
Line of credit facility borrowings outstanding due period	2015-04
Mexican Joint Venture Credit Facility | Senior Secured Credit Facility Revolving Line Of Credit | Second Line of Credit
Line of Credit Facility [Line Items]
Line of credit facility maximum capacity	30,000,000
Line of credit maturity date	2015-01
Mexican Joint Venture Credit Facility | Senior Secured Credit Facility Revolving Line Of Credit | LIBOR | First Line of Credit
Line of Credit Facility [Line Items]
Debt instrument, percentage points added to the reference rate	2.50%
Mexican Joint Venture Credit Facility | Senior Secured Credit Facility Revolving Line Of Credit | LIBOR | Second Line of Credit
Line of Credit Facility [Line Items]
Debt instrument, percentage points added to the reference rate	2.00%
European Credit Facilities | Senior Secured Credit Facility Revolving Line Of Credit
Line of Credit Facility [Line Items]
Line of credit facility maximum capacity	$ 18,200,000
European Credit Facilities | Senior Secured Credit Facility Revolving Line Of Credit | Minimum
Line of Credit Facility [Line Items]
Line of credit maturity date	2015-03
European Credit Facilities | Senior Secured Credit Facility Revolving Line Of Credit | Maximum
Line of Credit Facility [Line Items]
Line of credit maturity date	2016-02
European Credit Facilities | Senior Secured Credit Facility Revolving Line Of Credit | WIBOR | Minimum
Line of Credit Facility [Line Items]
Debt instrument, percentage points added to the reference rate	1.20%
European Credit Facilities | Senior Secured Credit Facility Revolving Line Of Credit | WIBOR | Maximum
Line of Credit Facility [Line Items]
Debt instrument, percentage points added to the reference rate	1.50%