CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 97,282	$ 72,833
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,049
Net foreign currency losses	318
Stock-based compensation	15,200
Deferred income taxes	(47,474)	4,296
Provision for (recovery from) bad debts	827
Other non-cash operating activities	217
Changes in assets and liabilities:
Accounts receivable	(16,464)	(3,656)
Contract assets	(41,928)	0
Contract costs	(2,546)	0
Prepaid expenses, prepaid income taxes, and other assets	1,744
Accounts payable, accrued expenses, income taxes payable and other liabilities	37,718
Deferred revenue	14,154	(41,586)
Net cash provided by operating activities	63,097	54,762
Cash flows from investing activities:
Purchases of property, equipment and leasehold improvements	(180)
Payments for business acquisitions	0
Payments for capitalized computer software costs	(189)
Net cash used in investing activities	(369)
Cash flows from financing activities:
Exercises of stock options	4,466
Repurchases of common stock	(147,423)
Payments of tax withholding obligations related to restricted stock	(9,654)
Deferred business acquisition payments	(1,200)
Proceeds from credit agreement	50,000
Payments of credit agreement issuance costs	0
Net cash used in financing activities	(103,811)
Effect of exchange rate changes on cash and cash equivalents	(654)
Decrease in cash and cash equivalents	(41,737)
Cash and cash equivalents, beginning of period	96,165
Cash and cash equivalents, end of period	54,428
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	5
Change in repurchases of common stock included in accounts payable and accrued expenses	2,577
Supplemental disclosure of cash flow information:
Income taxes paid, net	17,827
Interest paid	3,541
Accounting Standards Update 2014-09 [Member]
Cash flows from operating activities:
Net income		172,552
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		3,358
Net foreign currency losses		990
Stock-based compensation		11,869
Deferred income taxes		(90,781)
Provision for (recovery from) bad debts		(28)
Other non-cash operating activities		207
Changes in assets and liabilities:
Accounts receivable		(333)
Contract assets		(40,927)
Contract costs		(59)
Prepaid expenses, prepaid income taxes, and other assets		959
Accounts payable, accrued expenses, income taxes payable and other liabilities		(1,792)
Deferred revenue		(1,253)
Net cash provided by operating activities		54,762
Cash flows from investing activities:
Purchases of property, equipment and leasehold improvements		(156)
Payments for business acquisitions		(10,800)
Payments for capitalized computer software costs		(356)
Net cash used in investing activities		(11,312)
Cash flows from financing activities:
Exercises of stock options		3,548
Repurchases of common stock		(105,037)
Payments of tax withholding obligations related to restricted stock		(3,467)
Deferred business acquisition payments		(2,600)
Proceeds from credit agreement		11,000
Payments of credit agreement issuance costs		(351)
Net cash used in financing activities		(96,907)
Effect of exchange rate changes on cash and cash equivalents		206
Decrease in cash and cash equivalents		(53,251)
Cash and cash equivalents, beginning of period	$ 96,165	101,954
Cash and cash equivalents, end of period		48,703
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		(44)
Change in repurchases of common stock included in accounts payable and accrued expenses		(5,037)
Supplemental disclosure of cash flow information:
Income taxes paid, net		29,742
Interest paid		$ 2,039