Preferred Stock Subject To Mandatory Redemption - Additional Information (Detail) (USD $)	12 Months Ended		3 Months Ended		12 Months Ended	3 Months Ended	1 Months Ended	12 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2012 Series A Preferred Stock [Member]	May 31, 2012 Series A Preferred Stock [Member]	Aug. 31, 2012 Series A Preferred Stock [Member]	May 31, 2012 Series B Preferred Stock [Member]	Apr. 07, 2010 Series A 15% Cumulative Non-Voting Non-Convertible Preferred Stock, redeemable [Member]	Aug. 31, 2012 Series A 15% Cumulative Non-Voting Non-Convertible Preferred Stock, redeemable [Member] Y	Apr. 07, 2010 Series B Voting Convertible Preferred Stock [Member]
Preferred Stock [Line Items]
Preferred stock issued value		$ 100,000					$ 40,000,000		$ 7,700,000
Dividend on preferred stock (in percentage)							15.00%	6.00%
Preferred stock, shares issued (in shares)	0								100,000
Preferred Stock, shares authorized (in shares)	1,000,000
Preferred stock, shares par value (in USD per share)	$ 1.00
Preferred stock, shares outstanding (in shares)	0
Financial Instruments Subject to Mandatory Redemption, Settlement Terms, Fair Value of Shares							32,300,000
Amortization period of the discount on the Series A mandatory redeemable preferred stock (in years)								7
Dividend accrual outstanding (in percentage)								9.00%
Preferred stock, redeemed			28,900,000	20,000,000	28,900,000
Preferred stock, redeemed shares			58,750	41,250	41,250
Preferred stock redemption price			23,500,000	16,500,000	23,500,000
Accrued dividend			5,400,000	3,500,000	3,500,000
Accelerated accretion of Series A Preferred Stock discount included in non-operating income (expense)	1,000,000		3,200,000	2,300,000
Amortization of Series A Preferred Stock issuance costs included in non-operating income (expense)			$ 600,000	$ 500,000	$ 1,100,000
Preferred stock, converted						100,000
Common stock, Converted shares						1,000,000