Business Combination - Narrative (Details) $ / shares in Units, $ in Thousands		9 Months Ended
	Sep. 14, 2022 USD ($) $ / shares shares	Sep. 30, 2022 USD ($) $ / shares shares	Dec. 31, 2021 $ / shares shares
Business Acquisition [Line Items]
Shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, authorized (in shares)	950,000,000	950,000,000	950,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001	$ 0.0001
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Recapitalization exchange ratio	1.45590
Common stock - Legacy Amprius (in shares)	65,777,000
Options outstanding (in shares)	14,223,000
Shares subject to vesting obligations (in shares)	6,665,000
Sale of stock, price (in dollars per share) | $ / shares	$ 10.00
Common stock - PIPE Investment (in shares)	2,052,000
Number of common shares per PIPE unit (in shares)	1
Number of warrants per PIPE unit (in shares)	1
Proceeds from reverse recapitalization transaction | $	$ 70,938
Transaction costs paid | $		$ 6,794
Public warrants
Business Acquisition [Line Items]
Exercise price (in dollars per share) | $ / shares	$ 11.50
Warrants outstanding (in shares)	29,483,000
Private warrants
Business Acquisition [Line Items]
Exercise price (in dollars per share) | $ / shares	$ 11.50
Warrants outstanding (in shares)	16,400,000
PIPE warrants
Business Acquisition [Line Items]
Exercise price (in dollars per share) | $ / shares	$ 12.50
Warrants outstanding (in shares)	2,052,000
Average price per share of redeemable warrants (in dollars per share) | $ / shares	$ 20.00