Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
ASSETS
Cash and cash equivalents	$ 398,697	$ 275,458
Short-term marketable securities	0	28,129
Accounts receivable, net of allowance for doubtful accounts of $519 and $543 at December 31, 2020 and September 30, 2020, respectively	415,835	415,221
Prepaid expenses	72,877	69,408
Other current assets	48,795	45,231
Total current assets	936,204	833,447
Property and equipment, net	98,278	101,499
Goodwill	1,635,281	1,625,786
Acquired intangible assets, net	225,896	237,570
Long-term marketable securities	0	30,970
Deferred tax assets	186,536	190,963
Operating right-of-use lease assets	145,252	149,933
Other assets	221,441	212,570
Total assets	3,448,888	3,382,738
LIABILITIES AND STOCKHOLDERS’ EQUITY
Accounts payable	30,015	24,910
Accrued expenses and other current liabilities	123,197	96,313
Accrued compensation and benefits	94,389	101,087
Accrued income taxes	9,808	7,011
Deferred revenue	424,701	416,804
Short-term lease obligations	30,128	34,635
Total current liabilities	712,238	680,760
Long-term debt	987,857	1,005,314
Deferred tax liabilities	11,852	12,431
Deferred revenue	9,354	9,661
Long-term lease obligations	176,318	180,388
Other liabilities	56,340	55,936
Total liabilities	1,953,959	1,944,490
Commitments and contingencies (Note 15)
Stockholders’ equity:
Preferred stock, $0.01 par value; 5,000 shares authorized; none issued	0	0
Common stock, $0.01 par value; 500,000 shares authorized; 116,664 and 116,125 shares issued and outstanding at December 31, 2020 and September 30, 2020, respectively	1,167	1,161
Additional paid-in capital	1,623,379	1,602,728
Accumulated deficit	(38,752)	(62,267)
Accumulated other comprehensive loss	(90,865)	(103,374)
Total stockholders’ equity	1,494,929	1,438,248
Total liabilities and stockholders’ equity	$ 3,448,888	$ 3,382,738