Segment Reporting (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Feb. 28, 2013	Aug. 31, 2012	Feb. 29, 2012	Aug. 31, 2011
Segment Reporting Information [Line Items]
Revenues		$ 128,957		$ 127,755
Depreciation and amortization	19,842	19,842	19,459	19,459
Operating income	25,147	25,147	29,699	29,699
Capital expenditures	6,106	6,106	12,796	12,796
Total assets	2,018,660			2,035,816
Equity investments	142,899			150,402
Motorsports Event
Segment Reporting Information [Line Items]
Revenues		124,000		122,950
Depreciation and amortization		18,448		17,854
Operating income		27,070		31,383
Capital expenditures		5,739		12,036
Total assets	1,638,377			1,659,820
Equity investments
All Other
Segment Reporting Information [Line Items]
Revenues		4,957		4,805
Depreciation and amortization		1,394		1,605
Operating income		(1,923)		(1,684)
Capital expenditures		367		760
Total assets	380,283			375,996
Equity investments	$ 142,899			$ 150,402