Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Sep. 30, 2020
ASSETS
Cash and cash equivalents	$ 326,081	$ 275,458
Short-term marketable securities	0	28,129
Accounts receivable, net of allowance for doubtful accounts of $520 and $543 at March 31, 2021 and September 30, 2020, respectively	434,533	415,221
Prepaid expenses	86,719	69,408
Other current assets	54,430	45,231
Total current assets	901,763	833,447
Property and equipment, net	97,260	101,499
Goodwill	2,193,632	1,625,786
Acquired intangible assets, net	410,310	237,570
Long-term marketable securities	0	30,970
Deferred tax assets	182,176	190,963
Operating right-of-use lease assets	148,684	149,933
Other assets	247,396	212,570
Total assets	4,181,221	3,382,738
LIABILITIES AND STOCKHOLDERS’ EQUITY
Accounts payable	22,230	24,910
Accrued expenses and other current liabilities	124,244	96,313
Accrued compensation and benefits	94,641	101,087
Accrued income taxes	16,707	7,011
Deferred revenue	480,861	416,804
Short-term lease obligations	28,137	34,635
Total current liabilities	766,820	680,760
Long-term debt	1,508,389	1,005,314
Deferred tax liabilities	11,270	12,431
Deferred revenue	11,560	9,661
Long-term lease obligations	178,247	180,388
Other liabilities	54,402	55,936
Total liabilities	2,530,688	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; 116,855 and 116,125 shares issued and outstanding at March 31, 2021 and September 30, 2020, respectively	1,169	1,161
Additional paid-in capital	1,676,791	1,602,728
Retained earnings (accumulated deficit)	70,510	(62,267)
Accumulated other comprehensive loss	(97,937)	(103,374)
Total stockholders’ equity	1,650,533	1,438,248
Total liabilities and stockholders’ equity	$ 4,181,221	$ 3,382,738