CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
Current assets:
Cash and cash equivalents	$ 119,546	$ 136,067
Marketable securities	17,096	11,662
Accounts receivable, net of allowances of $538 and $1,394	59,091	50,900
Deferred costs	7,002	7,256
Prepaid expenses and other current assets	51,234	44,220
Total current assets	253,969	250,105
Property and equipment, net	29,544	29,529
Deferred costs	34,668	38,161
Operating lease right of use assets	19,189	20,096
Goodwill	1,130,502	1,128,198
Intangible assets, net	35,536	45,616
Deferred tax assets	167,264	160,974
Other assets	19,275	14,938
Total assets	1,689,947	1,687,617
Current liabilities:
Accounts payable	4,002	8,447
Deferred revenue	90,402	112,156
Short-term operating lease liabilities	5,602	5,700
Short-term debt	6,250	6,250
Accrued expenses and other current liabilities	55,042	66,078
Total current liabilities	161,298	198,631
Long-term debt	265,681	266,872
Deferred revenue, net of current portion	211,399	212,573
Long-term operating lease liabilities	13,987	17,821
Other liabilities	34,141	31,649
Total liabilities	686,506	727,546
Commitments and contingencies (Note 13)
Stockholders' Equity:
Common stock, $0.01 par value, 560,000 shares authorized; 37,780 shares issued and outstanding as of March 31, 2021; 36,842 shares issued and outstanding as of September 30, 2020.	379	369
Accumulated other comprehensive income	5,634	3,711
Additional paid-in capital	983,640	974,307
Retained earnings (accumulated deficit)	13,788	(18,316)
Total stockholders' equity	1,003,441	960,071
Total liabilities and stockholders' equity	$ 1,689,947	$ 1,687,617