v3.26.1
Summary of significant accounting policies - Loan receivables from Xiaoying Credit Loans and other loans, net (Details)
12 Months Ended
Dec. 31, 2025
CNY (¥)
Dec. 31, 2025
USD ($)
Dec. 31, 2024
CNY (¥)
Dec. 31, 2024
USD ($)
Dec. 31, 2023
CNY (¥)
Dec. 31, 2022
CNY (¥)
Accounts, Notes, Loans and Financing Receivable [Line Items]            
Loan receivable from Xiaoying, net ¥ 5,298,631,388 $ 757,694,211 ¥ 4,828,316,995      
Accrued interest receivable ¥ 79,152,472 11,318,653 71,667,521      
Charges off policy of Loans receivables (in days) 60 days          
Allowance for credit losses on loans receivable ¥ 236,233,265 33,780,908 175,820,629 $ 25,142,016 ¥ 188,719,449 ¥ 106,479,154
Xiaoying Credit Loans and other loans            
Accounts, Notes, Loans and Financing Receivable [Line Items]            
Loan receivable from Xiaoying, net 5,298,631,388 757,694,211 ¥ 4,828,316,995      
Loans facilitated in 2024 | Xiaoying Credit Loans and other loans            
Accounts, Notes, Loans and Financing Receivable [Line Items]            
Allowance for credit losses on loans receivable 123,023,655 17,592,149        
Loans Facilitated In 2025 | Xiaoying Credit Loans and other loans            
Accounts, Notes, Loans and Financing Receivable [Line Items]            
Allowance for credit losses on loans receivable ¥ 184,453,389 $ 26,376,484