Note 4. Fair Value Measures (Detail) - Assets and Liabilities Measured at Fair Value (USD $) In Thousands, unless otherwise specified	Nov. 30, 2012		Aug. 31, 2012
Cash and cash equivalents	$ 170,222		$ 160,169
Investments (short-term)	14,527	[1]	13,919	[1]
Total assets measured at fair value	184,749		174,088
Accounts payable and accrued liabilities (derivative liabilities)	343		2,374
Total liabilities measured at fair value	343		2,374
Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	170,222		160,169
Investments (short-term)	0	[1]	0	[1]
Total assets measured at fair value	170,222		160,169
Accounts payable and accrued liabilities (derivative liabilities)	0		0
Total liabilities measured at fair value	0		0
Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents	0		0
Investments (short-term)	14,527	[1]	13,919	[1]
Total assets measured at fair value	14,527		13,919
Accounts payable and accrued liabilities (derivative liabilities)	343		2,374
Total liabilities measured at fair value	343		2,374
Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents	0		0
Investments (short-term)	0	[1]	0	[1]
Total assets measured at fair value	0		0
Accounts payable and accrued liabilities (derivative liabilities)	0		0
Total liabilities measured at fair value	$ 0		$ 0

[1] The Company's certificates of deposit held for investment are not debt securities and are classified as Level 2. These certificates of deposit have original maturities greater than three months, but less than one year and, as such, are classified as investments (short-term) on the Company's consolidated balance sheet.