Revenue, Performance Obligations, Deferred Revenue and Deferred Costs - Schedule of Subscription and Transaction Fees Disaggregated by Customer Category (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Disaggregation Of Revenue [Line Items]
Total revenue	$ 42,110	$ 41,230	$ 39,080	$ 35,180	$ 31,684	$ 28,244	$ 25,999	$ 22,424	$ 157,600	$ 108,351	$ 64,865
Subscription and Transaction Fees
Disaggregation Of Revenue [Line Items]
Total revenue	$ 38,801	$ 36,092	$ 32,964	$ 28,548	$ 25,225	$ 22,112	$ 20,444	$ 18,170	136,405	85,951	56,992
Small-to-midsize Business and Accounting Firm Customers | Subscription and Transaction Fees
Disaggregation Of Revenue [Line Items]
Total revenue									126,035	76,292	50,138
Financial Institution Customers | Subscription and Transaction Fees
Disaggregation Of Revenue [Line Items]
Total revenue									$ 10,370	$ 9,659	$ 6,854