Short-Term and Long-Term Debts - Summary of Long-Term Debts (Detail)	Dec. 31, 2021 CNY (¥)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 CNY (¥)
Debt Instrument [Line Items]
Long-term debts	¥ 1,424,386,034	$ 223,517,251	¥ 2,206,574,921
Long Term Borrowings [Member]
Debt Instrument [Line Items]
Long-term debts, Term			36 months
Long-term debts	¥ 469,941,863	$ 73,744,133	¥ 107,055,556
Long Term Borrowings [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Long-term debts, Fixed annual rate	4.45%	4.45%	4.75%
Long-term debts, Term	15 months	15 months
Long Term Borrowings [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Long-term debts, Fixed annual rate	6.00%	6.00%	6.00%
Long-term debts, Term	36 months	36 months
Securitization Debts Payable [Member]
Debt Instrument [Line Items]
Long-term debts			¥ 401,761,874
Securitization Debts Payable [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Long-term debts, Fixed annual rate			4.73%
Long-term debts, Term			18 months
Securitization Debts Payable [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Long-term debts, Fixed annual rate			6.00%
Long-term debts, Term			20 months
Co-financing Debt Payables [Member]
Debt Instrument [Line Items]
Long-term debts	¥ 954,444,171	$ 149,773,118	¥ 1,697,757,491
Co-financing Debt Payables [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Long-term debts, Fixed annual rate	5.50%	5.50%	5.50%
Long-term debts, Term	24 months	24 months	24 months
Co-financing Debt Payables [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Long-term debts, Fixed annual rate	6.60%	6.60%	6.60%
Long-term debts, Term	36 months	36 months	36 months

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate.

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Period between issuance and maturity of long-term debt, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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