Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
	Aug. 31, 2018 USD ($)	Aug. 31, 2017 USD ($)	Aug. 31, 2016 USD ($)
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 267,085	$ 258,259	$ 338,815
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	57,285	48,294	38,052
Stock-based compensation expense	31,516	34,183	29,793
Loss (gain) on sale of business		1,223	(112,453)
Deferred income taxes	(1,910)	4,879	4,528
Loss (gain) on sale of assets	140	59	8
Tax benefits from share-based payment arrangements		(10,331)	(18,205)
Changes in assets and liabilities, net of effects of acquisitions
Accounts receivable, net of reserves	(8,417)	(29,503)	(3,541)
Accounts payable and accrued expenses	12,077	(2,226)	5,525
Accrued compensation	5,735	6,427	3,961
Deferred fees	6,035	(229)	700
Taxes payable, net of prepaid taxes	27,659	7,877	30,270
Prepaid expenses and other assets	(11,224)	(850)	7
Deferred rent and other non-current liabilities	(465)	2,331	13,674
Other working capital accounts, net	152	132	6
Net cash provided by operating activities	385,668	320,527	331,140
CASH FLOWS FROM INVESTING ACTIVITIES:
Acquisition of businesses and investments, net of cash and cash equivalents acquired	(15,000)	(303,086)	(262,909)
Proceeds from sale of business, net			153,137
Purchases of investments	(12,470)	(30,757)	(18,137)
Proceeds from sales of investments	12,459	23,399	17,241
Purchases of property, equipment and leasehold improvements, net of proceeds from dispositions	(33,520)	(36,862)	(47,740)
Net cash used in investing activities	(48,531)	(347,306)	(158,408)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividend payments	(89,408)	(80,898)	(74,218)
Repurchase of common stock	(303,955)	(260,978)	(356,828)
Proceeds from debt		640,000	265,000
Repayment of debt		(365,000)
Debt issuance costs		(438)	(12)
Proceeds from employee stock plans	71,610	50,045	56,851
Tax benefits from share-based payment arrangements		10,331	18,205
Other financing activities	1,716	(1,223)
Net cash used in financing activities	(320,037)	(8,161)	(91,002)
Effect of exchange rate changes on cash and cash equivalents	(3,208)	1,264	(12,237)
Net increase (decrease) in cash and cash equivalents	13,892	(33,676)	69,493
Cash and cash equivalents at beginning of period	194,731	228,407	158,914
Cash and cash equivalents at end of period	208,623	194,731	228,407
Supplemental Disclosure of Cash Flow Information
Cash paid during the year for interest	15,676	8,466	3,010
Cash paid during the year for income taxes, net of refunds	68,707	74,788	87,513
Supplemental Disclosure of Non-Cash Transactions
Dividends declared, not paid	$ 24,443	$ 21,853	$ 20,019