Summary of AMS Amounts Included in Discontinued Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2014	May 31, 2013
Discontinued Operations And Disposal Groups [Abstract]
Net revenue	$ 82,821	$ 271,543	$ 575,592	$ 786,237
Income from discontinued operations, before tax	3,378	10,518	27,164	43,128
Income tax expense	679	139	5,649	5,623
Income from discontinued operations, net of tax	2,699	10,379	21,515	37,505
Gain on sale of discontinued operations, before tax	248,275		239,320
Income tax expense	9,778		9,778
Gain on sale of discontinued operations, net of tax	238,497		229,542
Discontinued operations, net of tax	$ 241,196	$ 10,379	$ 251,057	$ 37,505