Finance Receivables, Net - Aging of Finance Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025	Sep. 30, 2025	Sep. 30, 2024
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	$ 222,946	$ 256,600	$ 268,855
Finance receivable, before allowance for credit loss, premium and discount			268,855
Current Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	172,101
Prior Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost			49,052
Finance receivable, before allowance for credit loss, premium and discount			210,113
Two Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost				$ 1,793
Finance receivable, before allowance for credit loss, premium and discount			57,523
Three Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivable, before allowance for credit loss, premium and discount			1,219
Financial Asset, 1 to 29 Days Past Due
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	24,445
Finance receivable, before allowance for credit loss, premium and discount			28,570
Financial Asset, 1 to 29 Days Past Due \| Current Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	18,666
Financial Asset, 1 to 29 Days Past Due \| Prior Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost			5,547
Finance receivable, before allowance for credit loss, premium and discount			22,166
Financial Asset, 1 to 29 Days Past Due \| Two Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost				232
Finance receivable, before allowance for credit loss, premium and discount			6,252
Financial Asset, 1 to 29 Days Past Due \| Three Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivable, before allowance for credit loss, premium and discount			152
Financial Asset, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	13,964
Finance receivable, before allowance for credit loss, premium and discount			18,290
Financial Asset, 30 to 59 Days Past Due \| Current Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	10,308
Financial Asset, 30 to 59 Days Past Due \| Prior Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost			3,480
Finance receivable, before allowance for credit loss, premium and discount			13,912
Financial Asset, 30 to 59 Days Past Due \| Two Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost				176
Finance receivable, before allowance for credit loss, premium and discount			4,243
Financial Asset, 30 to 59 Days Past Due \| Three Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivable, before allowance for credit loss, premium and discount			135
Financial Asset, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	13,493
Finance receivable, before allowance for credit loss, premium and discount			14,437
Financial Asset, 60 to 89 Days Past Due \| Current Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	9,309
Financial Asset, 60 to 89 Days Past Due \| Prior Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost			3,973
Finance receivable, before allowance for credit loss, premium and discount			10,338
Financial Asset, 60 to 89 Days Past Due \| Two Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost				211
Finance receivable, before allowance for credit loss, premium and discount			3,972
Financial Asset, 60 to 89 Days Past Due \| Three Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivable, before allowance for credit loss, premium and discount			127
Total past due
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	51,902
Finance receivable, before allowance for credit loss, premium and discount			61,297
Total past due \| Current Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	38,283
Total past due \| Prior Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost			13,000
Finance receivable, before allowance for credit loss, premium and discount			46,416
Total past due \| Two Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost				619
Finance receivable, before allowance for credit loss, premium and discount			14,467
Total past due \| Three Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivable, before allowance for credit loss, premium and discount			414
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	171,044
Finance receivable, before allowance for credit loss, premium and discount			207,558
Financial Asset, Not Past Due \| Current Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost	$ 133,818
Financial Asset, Not Past Due \| Prior Year
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost			36,052
Finance receivable, before allowance for credit loss, premium and discount			163,697
Financial Asset, Not Past Due \| Two Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivables, amortized cost				$ 1,174
Finance receivable, before allowance for credit loss, premium and discount			43,056
Financial Asset, Not Past Due \| Three Years Prior
Financing Receivable, Past Due [Line Items]
Finance receivable, before allowance for credit loss, premium and discount			$ 805