CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income	$ 262,734	$ 148,688	$ 162,196
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	8,143
Net foreign currency (gains) losses	(1,251)
Stock-based compensation	27,573
Deferred income taxes	(26,839)	3,193	(4,286)
Provision for bad debts	645
Tax benefits from stock-based compensation	0
Excess tax benefits from stock-based compensation	0
Other non-cash operating activities	429
Changes in assets and liabilities:
Accounts receivable	(6,626)	(4,327)	(7,480)
Contract assets	(59,322)	0	0
Contract costs	(4,482)	0	0
Prepaid expenses, prepaid income taxes, and other assets	(2,411)
Accounts payable, accrued expenses, income taxes payable and other liabilities	21,921
Deferred revenue	17,799	13,700	18,477
Net cash provided by operating activities	238,313	206,936	182,386
Cash flows from investing activities:
Purchases of marketable securities	0
Maturities of marketable securities	0
Purchase of property, equipment and leasehold improvements	(436)
Payments for business acquisitions, net of cash acquired	(6,098)
Payments for capitalized computer software costs	(1,131)
Net cash used in investing activities	(7,665)
Cash flows from financing activities:
Proceeds from issuances of shares of common stock	10,864
Repurchases of common stock	(299,214)
Payment of tax withholding obligations related to restricted stock	(14,477)
Deferred business acquisition payments	(1,700)
Excess tax benefits from stock-based compensation	0
Proceeds from credit agreement	50,000
Payments of credit agreement issuance costs	0
Net cash used in financing activities	(254,527)
Effect of exchange rate changes on cash and cash equivalents	(360)
Decrease in cash and cash equivalents	(24,239)
Cash and cash equivalents, beginning of year	96,165
Cash and cash equivalents, end of year	71,926	96,165
Supplemental disclosure of cash flow information:
Income tax paid, net	53,153
Interest paid	8,121
Supplemental disclosure of non-cash investing and financing activities:
Change in purchases of property, equipment and leasehold improvements included in accounts payable and accrued expenses	104
Change in repurchases of common stock included in accounts payable and accrued expenses	786
Accounting Standards Update 2014-09 (Topic 606) [Member]
Cash flows from operating activities:
Net income		293,703	179,386
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		6,544	6,405
Net foreign currency (gains) losses		980	(1,036)
Stock-based compensation		22,688	18,800
Deferred income taxes		(110,308)	5,273
Provision for bad debts		1,418	199
Tax benefits from stock-based compensation		0	5,965
Excess tax benefits from stock-based compensation		0	(5,965)
Other non-cash operating activities		421	602
Changes in assets and liabilities:
Accounts receivable		846	(8,164)
Contract assets		3,640	(4,327)
Contract costs		(617)	(203)
Prepaid expenses, prepaid income taxes, and other assets		3,821	(2,421)
Accounts payable, accrued expenses, income taxes payable and other liabilities		1,156	(9,070)
Deferred revenue		(17,356)	(3,058)
Net cash provided by operating activities		206,936	182,386
Cash flows from investing activities:
Purchases of marketable securities		0	(683,748)
Maturities of marketable securities		0	686,346
Purchase of property, equipment and leasehold improvements		(331)	(2,720)
Payments for business acquisitions, net of cash acquired		(33,700)	(36,171)
Payments for capitalized computer software costs		(329)	(405)
Net cash used in investing activities		(34,360)	(36,698)
Cash flows from financing activities:
Proceeds from issuances of shares of common stock		13,466	9,273
Repurchases of common stock		(205,049)	(371,491)
Payment of tax withholding obligations related to restricted stock		(7,896)	(5,764)
Deferred business acquisition payments		(8,649)	0
Excess tax benefits from stock-based compensation		0	5,965
Proceeds from credit agreement		30,000	0
Payments of credit agreement issuance costs		(351)	0
Net cash used in financing activities		(178,479)	(362,017)
Effect of exchange rate changes on cash and cash equivalents		114	(53)
Decrease in cash and cash equivalents		(5,789)	(216,382)
Cash and cash equivalents, beginning of year	$ 96,165	101,954	318,336
Cash and cash equivalents, end of year		96,165	101,954
Supplemental disclosure of cash flow information:
Income tax paid, net		50,557	65,536
Interest paid		5,038	3,444
Supplemental disclosure of non-cash investing and financing activities:
Change in purchases of property, equipment and leasehold improvements included in accounts payable and accrued expenses		(61)	(47)
Change in repurchases of common stock included in accounts payable and accrued expenses		$ (5,049)	$ 3,509