Postretirement Plans - Additional Information (Detail) - USD ($)	3 Months Ended			4 Months Ended		9 Months Ended
	Oct. 03, 2020	Oct. 05, 2019	Jul. 13, 2019	Apr. 18, 2020	Apr. 20, 2019	Oct. 03, 2020	Oct. 05, 2019
Plan No. 1
Pension and Other Postretirement Benefits Disclosure [Line Items]
Defined benefit plan assets, transferred				$ 6,400,000
Voluntarily contributions made by an employer		$ 0	$ 0	1,400,000	$ 0
Defined benefit plan, loan issued				5,000,000.0
Defined benefit plans non-cash settlement charge	$ 109,100,000			116,200,000		$ 109,100,000
Settlement loss				111,900,000		104,800,000	$ 0
Defined benefit plan obligation, curtailment loss				4,300,000		$ 4,300,000
Defined benefit plan, received refund of premium amount	7,100,000
Defined benefit plan amount				$ 700,000
Plan No. 2
Pension and Other Postretirement Benefits Disclosure [Line Items]
Voluntarily contributions made by an employer	$ 7,600,000	$ 2,500,000