Segment Reporting - Company's Revenue by Geographic Region Based on Bill-to Location (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2025	Apr. 30, 2024
Revenue from External Customer [Line Items]
Total revenue	$ 85,872	$ 54,473
Taiwan [Member]
Revenue from External Customer [Line Items]
Total revenue	53,899	33,685
Asia Pacific other than Taiwan [Member]
Revenue from External Customer [Line Items]
Total revenue	16,559	12,750
Europe [Member]
Revenue from External Customer [Line Items]
Total revenue	8,739	4,199
North America other than United States [Member]
Revenue from External Customer [Line Items]
Total revenue	5,145	2,770
United States [Member]
Revenue from External Customer [Line Items]
Total revenue	$ 1,530	$ 1,069

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details

AMBARELLA INC 10-Q