Benefits Expected to be Paid from Plans Assets (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Pension plans
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Benefits paid		$ 23,843	$ 24,408
2019		31,431
2020		327,280
2021		2,630
2022		2,715
2023		2,585
2024 – 2028		11,135
Pension plans | Includes Plan No 1 and No 2 Single Lump Sum
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Benefits paid	[1]			$ 40,864
Pension plans | Includes Plan No 1 and No 2 Single Lump Sum
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Benefits paid	[2]		38,776
Pension plans | Includes Plan No 1 and No 2 Single Lump Sum
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Benefits paid	[3]	48,722
Postretirement Benefit Plans
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Benefits paid		2,131	706
Postretirement Benefit Plans | Employer Gross Contribution
Schedule of Pension and Other Postretirement Benefits Expected Benefit Payments [Line Items]
Benefits paid		1,308	$ 376	$ 841
2019		1,041
2020		867
2021		812
2022		732
2023		696
2024 – 2028		$ 3,608

[1] Includes $15.7 million and $1.6 million from Plan No. 1 and Plan No. 2, respectively, paid as lump sums.

[2] Includes $14.4 million and $1.6 million from Plan No. 1 and Plan No. 2, respectively, paid as lump sums.

[3] Includes $24.9 million and $1.5 million from Plan No. 1 and Plan No. 2, respectively, paid as lump sums.