Reverse Recapitalization - Summary of Number of Shares of Common Stock Issued Immediately Following The Consummation of The Business Combination (Detail) - shares	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Feb. 13, 2021
Number Of Shares Of Common Stock Issued Immediately Following The Consummation Of The Business Combination [Line Items]
Common shares, shares outstanding	98,498,731	57,020,151
Stock Issued During Period, Shares, New Issues	83,412,347
Total Shares from Business Combination and PIPE Financing	11,927,204
Legacy Quanergy Shares [Member]
Number Of Shares Of Common Stock Issued Immediately Following The Consummation Of The Business Combination [Line Items]
Stock Issued During Period, Shares, New Issues	71,485,143
PIPE [Member]
Number Of Shares Of Common Stock Issued Immediately Following The Consummation Of The Business Combination [Line Items]
Stock Issued During Period, Shares, New Issues	3,695,000
Shares Issued Immediately following the consummation of the Business Combination [Member]
Number Of Shares Of Common Stock Issued Immediately Following The Consummation Of The Business Combination [Line Items]
Stock Issued During Period, Shares, New Issues	83,412,347
Common Class A [Member]
Number Of Shares Of Common Stock Issued Immediately Following The Consummation Of The Business Combination [Line Items]
Less: redemption of CCAC Class A Ordinary Shares	(26,267,796)
Common Class A [Member] | Prior to Business Combination [Member]
Number Of Shares Of Common Stock Issued Immediately Following The Consummation Of The Business Combination [Line Items]
Common shares, shares outstanding	27,600,000		27,600,000
Common Class B [Member] | Prior to Business Combination [Member]
Number Of Shares Of Common Stock Issued Immediately Following The Consummation Of The Business Combination [Line Items]
Common shares, shares outstanding	6,900,000