CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020
Current assets:
Cash and cash equivalents	$ 120,840	$ 136,067
Marketable securities	29,100	11,662
Accounts receivable, net of allowances of $404 and $1,394	53,141	50,900
Deferred costs	7,330	7,256
Prepaid expenses and other current assets	61,328	44,220
Total current assets	271,739	250,105
Long-term marketable securities	7,348
Property and equipment, net	30,723	29,529
Deferred costs	33,446	38,161
Operating lease right of use assets	16,837	20,096
Goodwill	1,132,897	1,128,198
Intangible assets, net	30,618	45,616
Deferred tax assets	165,077	160,974
Other assets	20,354	14,938
Total assets	1,709,039	1,687,617
Current liabilities:
Accounts payable	11,187	8,447
Deferred revenue	84,993	112,156
Short-term operating lease liabilities	5,497	5,700
Short-term debt	6,250	6,250
Accrued expenses and other current liabilities	60,955	66,078
Total current liabilities	168,882	198,631
Long-term debt	265,372	266,872
Deferred revenue, net of current portion	204,790	212,573
Long-term operating lease liabilities	13,157	17,821
Other liabilities	34,989	31,649
Total liabilities	687,190	727,546
Commitments and contingencies (Note 13)
Stockholders' Equity:
Common stock, $0.01 par value, 560,000 shares authorized; 37,828 shares issued and outstanding as of June 30, 2021; 36,842 shares issued and outstanding as of September 30, 2020.	379	369
Accumulated other comprehensive income	9,579	3,711
Additional paid-in capital	992,305	974,307
Retained earnings (accumulated deficit)	19,586	(18,316)
Total stockholders' equity	1,021,849	960,071
Total liabilities and stockholders' equity	$ 1,709,039	$ 1,687,617