Income Taxes - Components of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets related to:
Expenses not yet deducted for tax purposes	$ 343,308	$ 271,358
Operating lease liabilities	289,114	281,853
Pension liability not yet deducted for tax purposes	257,526	261,909
Capital loss	10,875	18,317
Net operating loss	56,028	43,932
Net deferred tax assets, gross	956,851	877,369
Deferred tax liabilities related to:
Employee and retiree benefits	226,356	215,899
Inventory	90,213	92,577
Operating lease assets	282,486	274,630
Other intangible assets	365,825	343,649
Property, plant and equipment	73,333	63,518
Other	29,961	38,936
Deferred tax liabilities, total	1,068,174	1,029,209
Net deferred tax liability before valuation allowance	(111,323)	(151,840)
Valuation allowance	(35,930)	(35,282)
Total net deferred tax liability	$ (147,253)	$ (187,122)