Derivative Financial Instruments and Hedging - Schedule of Derivative Instruments Gain (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Jan. 01, 2023	Jan. 02, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives gain (loss) on hedge transactions	$ (28.5)	$ 53.8	$ 15.5
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (a)	(2.5)	42.8	$ 11.4
Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives gain (loss) on hedge transactions	(21.8)	41.0
Cost of Sales and Interest Expense [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (a)	(1.9)	32.6
Nickel and other raw material contracts [Member] | Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives gain (loss) on hedge transactions	(11.0)	27.1
Nickel and other raw material contracts [Member] | Cost of Sales [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (a)	2.5	20.5
Natural gas contracts [Member] | Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives gain (loss) on hedge transactions	(11.3)	10.9
Natural gas contracts [Member] | Cost of Sales [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (a)	(5.7)	11.5
Foreign Exchange Contract [Member] | Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives gain (loss) on hedge transactions	0.2	0.7
Foreign Exchange Contract [Member] | Cost of Sales [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (a)	0.2	0.7
Interest Rate Swap [Member] | Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net derivatives gain (loss) on hedge transactions	0.3	2.3
Interest Rate Swap [Member] | Interest Expense [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income (a)	$ 1.1	$ (0.1)