Related Parties - Summary of Balances Outstanding with ATR's Minority Shareholder and Its Affiliates (Detail) ¥ in Thousands, $ in Thousands	Sep. 30, 2026 USD ($)	Sep. 30, 2026 CNY (¥)	Dec. 31, 2025 USD ($)	Dec. 31, 2025 CNY (¥)
Related Party Transaction [Line Items]
Accounts receivable from related parties	$ 71,652		$ 78,981
Accounts payable to related parties	41,115		46,268
Related Party [Member] \| ATR [Member]
Related Party Transaction [Line Items]
Accounts receivable from related parties	3,530	¥ 23,668	2,390	¥ 16,723
Accounts payable to related parties	$ 1,327	¥ 8,897	$ 69	¥ 481

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details