Business Combination - Summary of the Elements of the Business Combination to the Condensed Statements (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2021 USD ($) shares
Business Combination, Separately Recognized Transactions [Line Items]
Less: transaction costs allocated to equity	$ (19,042)
Effect of Business Combination, net of redemption and transaction costs	512,936
Effect of Business Combination, net of redemption and transaction costs	354,634
Conversion of convertible notes into common stock	50,198
Recognize earnout liability	(188,373)
Recognize private placement warrants liability	(19,395)
Recapitalization of Legacy Hyzon common shares	83
Less: transaction costs allocated to equity	$ (19,857)
Business Combination [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Total shares of Common Stock immediately after Business Combination \| shares	246,994,209
Ascent options [Member] \| Business Combination [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Total shares of Common Stock immediately after Business Combination \| shares	6,871,667
Legacy Hyzon [Member] \| Business Combination [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Total shares of Common Stock immediately after Business Combination \| shares	173,474,186
Conversion of Convertible Notes [Member] \| Business Combination [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Total shares of Common Stock immediately after Business Combination \| shares	5,022,052
DCRB trust [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Cash	$ 191,181
DCRB trust [Member] \| Business Combination [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Total shares of Common Stock immediately after Business Combination \| shares	26,126,304
PIPE Financing [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Cash	$ 340,797
PIPE Financing [Member] \| Business Combination [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Total shares of Common Stock immediately after Business Combination \| shares	35,500,000
Founders Shares [Member] \| DCRB trust [Member] \| Business Combination [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Total shares of Common Stock immediately after Business Combination \| shares	5,643,125
Common Stock [Member] \| Business Combination [Member] \| Common Class A [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Total shares of Common Stock immediately after Business Combination \| shares	73,520,023
Common Stock [Member] \| DCRB trust [Member] \| Business Combination [Member]
Business Combination, Separately Recognized Transactions [Line Items]
Total shares of Common Stock immediately after Business Combination \| shares	20,483,179

Effect of business combination, net of redemption and transaction costs.

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Recognize private placement warrants liability.

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Number of shares of equity interests issued or issuable to acquire entity.

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Amount of increase (decrease) in the value of right to a contingent consideration asset.

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Amount of liability recognized arising from contingent consideration in a business combination.

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For transactions that are recognized separately from the acquisition of assets and assumptions of liabilities in the business combination, such as related to pre-existing relationships with the acquiree, this element represents the disclosure of the amount of acquisition related costs which have been expensed.

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The expenses and losses recorded for each transaction with the acquiree that was recognized separately from the acquisition of assets and assumptions of liabilities in the business combination.

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The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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Amount of recapitalization costs for professional fees associated with restructuring debt and equity mixture that do not qualify for capitalization.

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