Financing receivables, net - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Sep. 30, 2024
Financing Receivable, Credit Quality Indicator [Line Items]
2025	$ 3,256
2024	2,965
2023	1,427
Total	7,648	$ 8,027
High
Financing Receivable, Credit Quality Indicator [Line Items]
2025	1,290
Total	1,290	0
Moderate
Financing Receivable, Credit Quality Indicator [Line Items]
2025	1,201
2024	395
2023	171
Total	1,767	874
Low
Financing Receivable, Credit Quality Indicator [Line Items]
2025	765
2024	2,570
2023	1,256
Total	$ 4,591	$ 7,153