Corporate information - Narrative (Details) $ / shares in Units, $ in Millions		2 Months Ended	12 Months Ended
	Aug. 10, 2021 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2023 USD ($) $ / shares shares	Oct. 31, 2022 USD ($) shares	Oct. 31, 2021 USD ($) $ / shares shares	Mar. 11, 2024 USD ($)	Oct. 23, 2023 USD ($)	Jan. 31, 2022 $ / shares	Aug. 11, 2021 shares	Oct. 31, 2020 USD ($) shares
Reverse Recapitalization [Line Items]
Common stock, shares, outstanding (in shares)		176,100,000	178,200,000	176,000,000	163,300,000				163,179,555
Stock converted, reverse recapitalization (in shares)	96,084,679
Class of warrant or right, outstanding (in shares)		0	0	0	22,999,894					0
Business combination exchange ratio	0.0251
Grants (in shares)		0	1,088,500	763,829	2,320,989
Sale of stock, number of shares issued in transaction (in shares)	31,549,000
Sale of stock, price per share (in dollars per share) | $ / shares	$ 10.00
Sale of stock, consideration received on transaction | $	$ 315.5
Class of warrant or right, exercise price of warrants or rights (in dollars per share) | $ / shares	$ 2.10		$ 11.50		$ 3.57			$ 11.50
Warrants | $	$ 48.3	$ 0.0	$ 0.0	$ 0.0	$ 82.1					$ 0.0
Cash and cash equivalents | $	581.9
Net cash proceeds acquired through reverse recapitalization | $	$ 525.3
Common stock, shares, issued (in shares)		176,100,000	178,200,000	176,000,000	163,300,000				163,179,555
Net (loss) income | $		$ 1.6	$ (138.0)	$ (50.3)	$ (70.5)
Net cash used in operating activities | $		40.9	99.8	77.0	25.6
Working capital | $			(7.7)
Property, plant and equipment, construction budget | $							$ 560.0
Glencore Convertible Notes
Reverse Recapitalization [Line Items]
Debt instrument, face amount | $			225.3
Glencore Convertible Notes | Convertible Debt
Reverse Recapitalization [Line Items]
Debt instrument, face amount | $		$ 208.1	$ 225.3	$ 200.0	$ 0.0					$ 0.0
Glencore Convertible Notes | Convertible Debt | Subsequent Event
Reverse Recapitalization [Line Items]
Debt instrument, face amount | $						$ 75.0
Peridot Acquisition Corp.
Reverse Recapitalization [Line Items]
Class of warrant or right, outstanding (in shares)	23,000,000
Reverse recapitalization, acquisition costs | $	$ 29.6
Li-Cycle Holdings Corp.
Reverse Recapitalization [Line Items]
Reverse recapitalization, acquisition costs | $	$ 27.0
Stock Election Shareholders | Li-Cycle Corp.
Reverse Recapitalization [Line Items]
Common stock, shares, outstanding (in shares)	2,552,450
Peridot Shareholders
Reverse Recapitalization [Line Items]
Reverse recapitalization, cash paid to shareholders | $	$ 33.8
Stock converted, reverse recapitalization (in shares)	7,500,000
Warrants converted, reverse recapitalization (in shares)	23,000,000
Li-Cycle Corp. Shareholders
Reverse Recapitalization [Line Items]
Stock converted, reverse recapitalization (in shares)	97,508,181
Grants (in shares)	4,242,707
Common Class A | Cash Election Stockholders | Peridot Acquisition Corp.
Reverse Recapitalization [Line Items]
Common stock, shares, outstanding (in shares)	3,377,626
Common Class A | Stock Election Shareholders | Peridot Acquisition Corp.
Reverse Recapitalization [Line Items]
Common stock, shares, outstanding (in shares)	26,622,374
Common Class B | Peridot Acquisition Corp.
Reverse Recapitalization [Line Items]
Common stock, shares, outstanding (in shares)	7,500,000