Unaudited Quarterly Financial Data (Tables)

12 Months Ended

Aug. 31, 2011

Unaudited Quarterly Financial Data [Abstract]

Schedule Of Quarterly Financial Data

2011	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Revenues	$	173,289	$	177,635	$	183,647	$	191,939
Cost of services		56,785		60,137		62,224		65,477
Selling, general and administrative		57,075		59,405		59,600		67,472
Operating income		59,429		58,093		61,823		58,990
Net income		41,601		45,254		43,311		40,880
Diluted earnings per common share	$	0.88	$	0.95	$	0.92	$	0.88
Weighted average common shares (diluted)		47,487		47,427		47,154		46,595
2010	First Quarter		Second Quarter		Third Quarter		Fourth Quarter
Revenues	$	155,243	$	157,281	$	160,301	$	168,234
Cost of services		50,407		50,870		51,355		53,918
Selling, general and administrative		50,789		51,938		53,262		56,886
Operating income		54,047		54,473		55,684		57,430
Net income		36,143		36,119		38,658		39,291
Diluted earnings per common share	$	0.74	$	0.75	$	0.81	$	0.83
Weighted average common shares (diluted)		48,876		48,066		47,725		47,280