Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013
Earnings Per Share [Abstract]
Earnings from continuing operations	$ 22,304	$ 25,834	$ 55,309	$ 56,385
Weighted average common shares outstanding - basic	72,227	72,946	72,656	72,869
Net effect of dilutive securities—stock based compensation plans	1,546	1,470	1,736	1,474
Weighted average common shares outstanding - diluted	73,773	74,416	74,392	74,343
Basic (in dollars per share)	$ 0.31	$ 0.35	$ 0.76	$ 0.77
Diluted (in dollars per share)	$ 0.30	$ 0.35	$ 0.74	$ 0.76
Anti-dilutive securities-stock based compensation plans (excluded from earnings per share calculation)	403	759	404	774