CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net income	$ 19,044	$ 20,941
Adjustments to reconcile net income to net cash provided by operations:
Depreciation and amortization	7,210	7,624
Benefit from credit loss reserve	(418)	(410)
Stock-based compensation	5,841	13,325
Non-cash interest expense	1,301	1,230
Deferred tax benefit	(1,455)	(16,137)
Other	551
Changes in operating assets and liabilities:
Accounts receivable	7,555	(7,155)
Prepaid expenses and other assets	(19,707)	1,025
Deferred costs	1,509	2,051
Accounts payable	(3,153)	(3,655)
Accrued expenses and other liabilities	(2,797)	(1,527)
Deferred revenue	(10,336)	(6,503)
Net cash provided by operating activities	5,145	10,809
Cash flows from investing activities:
Capital expenditures	(4,410)	(2,369)
Purchases of marketable securities	(3,593)	(6,358)
Sale and maturities of marketable securities	5,706
Other investing activities	559
Net cash used in investing activities	(1,738)	(8,727)
Cash flows from financing activities:
Payments for long-term debt issuance costs		(520)
Principal payments of long-term debt	(1,563)	(1,563)
Common stock repurchases for tax withholdings for net settlement of equity awards	(44,573)	(30,258)
Principal payment of lease liabilities arising from a finance lease	(155)	(101)
Proceeds from the issuance of common stock	32,139	3,663
Net cash used in financing activities	(14,152)	(28,779)
Effects of exchange rate changes on cash and cash equivalents	(447)	990
Net change in cash and cash equivalents	(11,192)	(25,707)
Cash and cash equivalents at beginning of period	128,428	136,067
Cash and cash equivalents at end of period	117,236	110,360
Supplemental information:
Cash paid for income taxes	2,455	563
Cash paid for interest	$ 3,392	$ 3,805