Revenue, Performance Obligations, Deferred Revenue and Unbilled Revenue - Schedule of Revenue from Subscription and Transaction Fees Disaggregated by Customer Category (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Mar. 31, 2022	Sep. 30, 2021	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Disaggregation Of Revenue [Line Items]
Total revenue	$ 166,911	$ 118,349	$ 59,738	$ 441,738	$ 159,992
Subscription and Transaction Fees
Disaggregation Of Revenue [Line Items]
Total revenue	165,468		58,622	438,546	154,743
Subscription and Transaction Fees | Small-to-midsize Business, Accounting Firm Customers and Other
Disaggregation Of Revenue [Line Items]
Total revenue	156,518		54,710	417,651	144,609
Subscription and Transaction Fees | Financial Institution Customers
Disaggregation Of Revenue [Line Items]
Total revenue	8,950		3,912	20,895	10,134
Interest on Funds Held for Customers
Disaggregation Of Revenue [Line Items]
Total revenue	$ 1,443		$ 1,116	$ 3,192	$ 5,249