Note 7. Segment Information (Detail) - Results of Operations (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	Feb. 28, 2013	Feb. 29, 2012	Aug. 31, 2012
Revenues from clients	$ 213,083	$ 199,371	$ 424,167	$ 395,819
Segment operating profit	56,164	67,117	127,248	133,870
Total assets	669,978	663,824	669,978	663,824	694,143
Capital expenditures	2,987	4,590	9,084	10,644
United States [Member]
Revenues from clients	146,034	136,415	289,975	270,892
Segment operating profit	24,525	37,565	64,125	74,001
Total assets	441,575	358,963	441,575	358,963
Capital expenditures	2,032	4,255	5,309	9,867
Europe [Member]
Revenues from clients	51,650	48,824	103,280	96,929
Segment operating profit	24,219	22,536	48,942	46,317
Total assets	176,317	258,805	176,317	258,805
Capital expenditures	164	156	717	211
Asia Pacific [Member]
Revenues from clients	15,399	14,132	30,912	27,998
Segment operating profit	7,420	7,016	14,181	13,552
Total assets	52,086	46,056	52,086	46,056
Capital expenditures	$ 791	$ 179	$ 3,058	$ 566