Leases - Future minimum rental payments for operating leases (Details)	Dec. 31, 2024 CNY (¥)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 CNY (¥)
Leases
1 year (Including 1 year)	¥ 19,881,698	$ 2,723,781	¥ 33,802,951
1 year to 2 years (Including 2 years)	15,925,475	2,181,781	23,258,088
2 years to 3 years (Including 3 years)	10,233,700	1,402,011	14,737,167
3 years to 4 years (Including 4 years)	9,335,618	1,278,974	4,802,888
4 years to 5 years (Including 5 years)	6,713,328	919,722	3,982,687
Over 5 years	14,278,622	1,956,163	934,146
Total lease payments	76,368,441	10,462,432	81,517,927
Less: imputed interest	8,965,407	1,228,254	11,820,823
Present value of lease liabilities	67,403,034	9,234,178	69,697,104
Less: Current portion	(18,696,986)	(2,561,477)	(29,937,993)
Long-term lease liabilities	¥ 48,706,048	$ 6,672,701	¥ 39,759,111

No definition available.

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-6

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease due after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of lessee's undiscounted obligation for lease payment for operating lease to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.

+ References

+ Details

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Present value of lessee's discounted obligation for lease payments from operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479041/842-20-45-1

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent.

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