Plans Fair Value of Plan Assets by Asset Class (Detail) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 29, 2018	Dec. 31, 2017	Dec. 30, 2017	Dec. 31, 2016
Pension plans
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		$ 335,540	$ 335,540	$ 340,854	$ 340,854	$ 335,663
Short Term Investments And Cash
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		34,118		19,771
Equity Securities | Us Companies
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets				65,414
Equity Securities | International Companies
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets				665
Equity Securities | International Equity Funds
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets	[1]			22,178
Equity Securities | Domestic Equity Funds
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets	[2]			19,879
Fixed Income Securities | US Treasury Securities
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		4,581		6,538
Fixed Income Securities | US Government Agencies Debt Securities
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		3,561		10,531
Fixed Income Securities | Domestic Corporate Debt Securities
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		166,670		9,993
Fixed Income Securities | International Corporate Bonds
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		53,709
Fixed Income Securities | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets				3,004
Pending Transactions
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets	[3]	59,452		62,000
Other Assets And Liabilities
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets and (liabilities)	[3]	2,636		(133)
Accrued (Expenses) Income
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets	[3]	(40)		(79)
Level 1 | Pension plans
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets				108,136
Level 1 | Equity Securities | Us Companies
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets				65,414
Level 1 | Equity Securities | International Companies
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets				665
Level 1 | Equity Securities | International Equity Funds
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets	[1]			22,178
Level 1 | Equity Securities | Domestic Equity Funds
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets	[2]			19,879
Level 2 | Pension plans
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		262,639		49,837
Level 2 | Short Term Investments And Cash
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		34,118		19,771
Level 2 | Fixed Income Securities | US Treasury Securities
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		4,581		6,538
Level 2 | Fixed Income Securities | US Government Agencies Debt Securities
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		3,561		10,531
Level 2 | Fixed Income Securities | Domestic Corporate Debt Securities
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		166,670		9,993
Level 2 | Fixed Income Securities | International Corporate Bonds
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets		53,709
Level 2 | Fixed Income Securities | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets				3,004
Other Investments Measured at Net Asset Value | International Equity Funds
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets	[1],[4]			22,878
Other Investments Measured at Net Asset Value | Hedge Funds, Equity
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets	[4],[5]			35,054
Other Investments Measured at Net Asset Value | Absolute Return Funds
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets	[4],[6]			52,704
Other Investments Measured at Contract Value | Guaranteed Insurance Contracts
Schedule of Pension Plan Assets by Fair Value [Line Items]
Fair value of plan assets	[7],[8]	$ 10,853		$ 10,457

[1] This class includes funds with the principal strategy to invest primarily in long positions in international equity securities. This asset was reclassified from a Level 2 to a Level 1 type for all periods. This asset was incorrectly presented as a Level 2.

[2] This class includes funds with the principal strategy to invest primarily in long positions in domestic equity securities.

[3] This class includes accrued interest, dividends, and amounts receivable from asset sales and amounts payable for asset purchases.

[4] Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy.

[5] This class invests primarily in hedged equity funds.

[6] This class invests primarily in absolute return strategy funds and are reported at NAV.

[7] Certain investments, which are fully-benefit responsive investment contracts, are measured at contract value and have not been classified in the fair value hierarchy.

[8] This class invests primarily guaranteed insurance contracts through various U.S. insurance companies.