Consolidated statements of equity - USD ($) $ in Millions	Total	Equity attributable to the shareholders of Li-Cycle Holdings Corp.	Number of common shares	Common stock and additional paid-in capital	Accumulated deficit	Accumulated other comprehensive loss	Non-controlling interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares, outstanding (in shares)			22,000,000.0
Beginning balance, equity at Dec. 31, 2022	$ 501.6	$ 501.4		$ 635.3	$ (133.6)	$ (0.3)	$ 0.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Settlement of RSUs (in shares)			100,000
Settlement of RSUs	$ 0.0
Exercise of stock options (in shares)	197,678		200,000
Exercise of stock options	$ 0.0
Stock-based compensation - RSUs	9.8	9.8		9.8
Stock-based compensation - options	3.6	3.6		3.6
Payment to the holders of non-controlling interest in subsidiary	(0.6)	(0.4)		(0.4)			(0.2)
Net loss	(138.0)	(138.0)			(138.0)
Comprehensive (loss) income	(138.0)	(138.0)			(138.0)
Ending balance, equity at Dec. 31, 2023	$ 376.4	376.4		648.3	(271.6)	(0.3)	0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares, outstanding (in shares)	22,300,000		22,300,000
Settlement of RSUs (in shares)			900,000
Settlement of RSUs	$ 0.0
Stock based compensation - PSUs	$ 0.1	0.1		0.1
Exercise of stock options (in shares)	10,086
Stock-based compensation - RSUs	$ 8.7	8.7		8.7
Stock-based compensation - options	0.1	0.1		0.1
Net loss	(137.7)	(137.7)			(137.7)
Comprehensive (loss) income	(137.7)	(137.7)			(137.7)
Issuance of common stock in connection with the ATM Program (in shares)			7,200,000
Issuance of common stock in connection with the ATM Program	15.5	15.5		15.5
Ending balance, equity at Dec. 31, 2024	$ 263.1	$ 263.1		$ 672.7	$ (409.3)	$ (0.3)	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, shares, outstanding (in shares)	30,400,000		30,400,000