Nature of Operations and Summary of Significant Accounting Policies - Narrative (Details)	3 Months Ended			6 Months Ended		12 Months Ended
	Mar. 31, 2022 USD ($) institution $ / shares	Sep. 30, 2021 USD ($) $ / shares	Mar. 31, 2021 USD ($)	Mar. 31, 2022 USD ($) institution reportingUnit segment $ / shares	Mar. 31, 2021 USD ($)	Dec. 31, 2017	Feb. 28, 2021 USD ($)	Feb. 05, 2021 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of financial services organizations, leading marketplace and financial technology brands (more than) | institution	7,500			7,500
Foreign currency translation gain (loss)	$ (1,862,000)		$ (2,648,000)	$ (3,129,000)	$ 112,000
Other-than-temporary impairment charges recognized	$ 0		0	$ 0	0
Common stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001		$ 0.001
Write-offs of allowance for doubtful accounts				$ 1,000	34,000
Allowance for doubtful accounts receivable	$ 500,000	$ 400,000		500,000
Capitalized software development costs for internal use	200,000		$ 200,000	400,000	400,000
Amortization expense from capitalized software development costs for internal use				$ 100,000	200,000
Number of operating segments | segment				1
Number of reporting units | reportingUnit				1
Goodwill impairment		0
Impairment charges related to intangible assets				$ 0	$ 0
Trading-day average stock price period (in days)				20 days
Accumulated other comprehensive loss	5,170,000	943,000		$ 5,170,000
Reclassification of embedded conversion derivative	0	(48,208,000)		0
Reclassification of Notes Hedge	0	(48,208,000)		0
Deferred tax impact of increase of authorized shares of common stock on convertible senior notes hedge
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of embedded conversion derivative	28,500,000			28,500,000
Reclassification of Notes Hedge	28,500,000			28,500,000
Convertible Debt | 2026 Notes
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt issued							$ 155,300,000	$ 155,300,000
Debt interest rate							0.75%	0.75%
HooYu | Spanish Government Agencies
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt interest rate						0.00%
Amount outstanding under loan agreement	800,000	800,000		800,000
HooYu | Spanish Government Agencies | Other current liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Current loans payable	100,000	100,000		100,000
HooYu | Spanish Government Agencies | Other non-current liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Noncurrent loans payable	$ 700,000	$ 700,000		$ 700,000
Minimum | HooYu | Spanish Government Agencies
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Term of loan agreement (in years)						5 years
Maximum | HooYu | Spanish Government Agencies
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Term of loan agreement (in years)						12 years