Note 8 - Segment Information - Results of Operations (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Feb. 28, 2019	Feb. 28, 2018	Feb. 28, 2019	Feb. 28, 2018	Aug. 31, 2018
Revenue from clients	$ 354,895	$ 335,231	$ 706,535	$ 664,372
Segment operating income	108,688	95,485	209,227	184,583
Total assets	1,464,994	1,472,492	1,464,994	1,472,492	$ 1,419,447
Capital expenditures	11,957	6,463	21,482	12,375
UNITED STATES
Revenue from clients	223,315	208,900	445,518	417,668
Segment operating income	45,696	38,527	89,537	79,298
Total assets	792,573	733,045	792,573	733,045
Capital expenditures	7,254	3,729	11,358	7,274
Europe [Member]
Revenue from clients	98,933	96,206	196,698	187,933
Segment operating income	43,248	36,993	82,337	69,963
Total assets	556,526	634,472	556,526	634,472
Capital expenditures	434	755	1,697	2,279
Asia Pacific [Member]
Revenue from clients	32,647	30,125	64,319	58,771
Segment operating income	19,744	19,965	37,353	35,322
Total assets	115,895	104,975	115,895	104,975
Capital expenditures	$ 4,269	$ 1,979	$ 8,427	$ 2,822

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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