v3.26.1
Summary of significant accounting policies - Movement of provision for loan receivables from Xiaoying Credit Loans and other loans (Details)
 12 Months Ended
Dec. 31, 2025
CNY (¥)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
CNY (¥)
Dec. 31, 2023
CNY (¥)
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loans receivable at beginning of the year ¥ 175,820,629 $ 25,142,016 ¥ 188,719,449 ¥ 106,479,154
(Reversal of) Provision for loans receivable from Xiaoying Credit Loans and other loans (net of recovery) 340,217,158 48,650,407 225,815,327 233,350,276
Charge-offs (279,804,522) (40,011,515) (238,714,147) (151,109,981)
Allowance for loans receivable at end of the year 236,233,265 33,780,908 175,820,629 188,719,449
Recoveries of charge-off of loans receivables 27,672,522 3,957,118 9,251,001 13,488,360
Xiaoying Credit Loans And Revolving Loans        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loans receivable at beginning of the year 175,820,629      
Allowance for loans receivable at end of the year 236,233,265   175,820,629  
Xiaoying Credit Loan        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loans receivable at beginning of the year 175,820,629 25,142,016 188,718,875 103,630,827
(Reversal of) Provision for loans receivable from Xiaoying Credit Loans and other loans (net of recovery) 340,274,053 48,658,542 226,865,598 234,237,584
Charge-offs (279,861,417) (40,019,650) (239,763,844) (149,149,536)
Allowance for loans receivable at end of the year 236,233,265 33,780,908 175,820,629 188,718,875
Xiaoying Revolving Loan        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loans receivable at beginning of the year 0   0 0
(Reversal of) Provision for loans receivable from Xiaoying Credit Loans and other loans (net of recovery)     (900,606) (2,737,290)
Charge-offs     (900,606) (2,737,290)
Allowance for loans receivable at end of the year     0 0
Other loans        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loans receivable at beginning of the year 0 0 574 2,848,327
(Reversal of) Provision for loans receivable from Xiaoying Credit Loans and other loans (net of recovery) (56,895) (8,135) (149,665) 1,849,982
Charge-offs (56,895) (8,135) (149,091) (4,697,735)
Allowance for loans receivable at end of the year 0 0 ¥ 0 ¥ 574
Xiaoying Credit Loans and other loans | Loans facilitated in 2024        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loans receivable at end of the year ¥ 123,023,655 $ 17,592,149