Segment and Geographic Information - Summary of Revenue and Profit Attributable to Our Operating Segments (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Revenue Reconciling Item [Line Items]
Revenue		$ 542,181	$ 505,227	$ 1,008,091	$ 962,948
Operating costs		113,506	93,337	209,296	188,455
Gross margin		428,675	411,890	798,795	774,493
Sales and marketing expenses		129,207	116,408	247,590	241,884
General and administrative expenses		65,923	47,469	116,894	99,409
Restructuring and other charges (credits), net		1	(1,562)	(337)	32,429
Intangibles amortization		20,490	14,371	34,658	29,348
Operating income		122,539	159,190	227,440	221,368
Interest and debt premium expense		(41,525)	(12,239)	(57,883)	(25,225)
Other income (expense), net		55	(43,385)	(2,064)	(37,201)
Income before income taxes		81,069	103,566	167,493	158,942
Operating Segments
Segment Reporting Revenue Reconciling Item [Line Items]
Revenue		542,181	505,227	1,008,091	962,948	[1]
Operating costs		182,695	155,583	344,987	308,594
Gross margin		359,486	349,644	663,104	654,354
Operating Segments | Software Products
Segment Reporting Revenue Reconciling Item [Line Items]
Revenue		501,064	462,250	931,418	875,843
Operating costs	[2]	147,865	121,016	278,593	237,044
Gross margin		353,199	341,234	652,825	638,799
Operating Segments | Professional Services
Segment Reporting Revenue Reconciling Item [Line Items]
Revenue		41,117	42,977	76,673	87,105
Operating costs	[3]	34,830	34,567	66,394	71,550
Gross margin		6,287	8,410	10,279	15,555
Unallocated
Segment Reporting Revenue Reconciling Item [Line Items]
Sales and marketing expenses		116,362	104,962	222,549	217,357
General and administrative expenses		35,965	30,859	67,355	65,036
Restructuring and other charges (credits), net		1	(1,562)	(337)	32,429
Intangibles amortization		20,490	14,371	34,658	29,348
Stock-based compensation		52,246	37,921	93,750	83,863
Other unallocated operating expenses	[4]	$ 11,883	$ 3,903	$ 17,689	$ 4,953

[1] Subsequent to filing our second quarter 2022 Form 10-Q, we identified an immaterial typographical error in the above disclosure. Revenue by region was transposed for Europe and Asia Pacific for the three and six-months ended March 31, 2022. Amounts presented above for the three and six months ended March 31, 2022 reflect the corrected amounts.

[2] Operating costs for the Software Products segment include all costs of software revenue and research and development costs, excluding stock-based compensation and intangible amortization.

[3] Operating costs for the Professional Services segment include all costs of professional services revenue, excluding stock-based compensation.

[4] Other unallocated operating expenses include acquisition and transaction-related costs.