Benefits - Defined benefit plans (Details) - USD ($) $ in Millions	12 Months Ended
	Nov. 30, 2025	Dec. 01, 2024	Nov. 26, 2023
Pension Benefits
Net periodic benefit cost (income):
Service cost	$ 2.9	$ 2.6	$ 2.8
Interest cost	35.4	39.7	39.9
Expected return on plan assets	(37.1)	(38.9)	(37.7)
Amortization of prior service benefit	0.0	(0.1)	(0.1)
Amortization of actuarial loss	7.0	8.0	8.9
Curtailment (gain)	0.0	(1.7)	0.0
Net settlement loss (gain)	0.5	1.0	18.9
Net periodic benefit cost	8.7	10.6	32.7
Changes in accumulated other comprehensive loss:
Actuarial (gain) loss	1.9	(6.9)	(7.9)
Amortization of prior service benefit (cost)	0.0	0.1	0.1
Amortization of actuarial loss	(7.0)	(8.0)	(8.9)
Net settlement (loss) gain	(0.5)	(1.0)	(18.9)
Total recognized in accumulated other comprehensive loss	(5.6)	(15.8)	(35.6)
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	3.1	(5.2)	(2.9)
Postretirement Benefits
Net periodic benefit cost (income):
Service cost	0.0	0.0	0.0
Interest cost	1.6	2.0	2.0
Expected return on plan assets	0.0	0.0	0.0
Amortization of prior service benefit	0.0	0.0	0.0
Amortization of actuarial loss	0.0	0.0	0.0
Curtailment (gain)	0.0	0.0	0.0
Net settlement loss (gain)	0.0	0.0	0.0
Net periodic benefit cost	1.6	2.0	2.0
Changes in accumulated other comprehensive loss:
Actuarial (gain) loss	(0.2)	0.5	1.0
Amortization of prior service benefit (cost)	0.0	0.0	0.0
Amortization of actuarial loss	0.0	0.0	0.0
Net settlement (loss) gain	0.0	0.0	0.0
Total recognized in accumulated other comprehensive loss	(0.2)	0.5	1.0
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	$ 1.4	$ 2.5	$ 3.0