Income Taxes - Components Of Companys Deferred Tax Assets and Liabilities (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred tax assets:
Postretirement and other employee benefits	$ 269,471	$ 243,222
Products liability	71,759	68,261
Net operating loss, capital loss, and tax credits carryforwards	30,043	36,924
All other items	49,103	41,635
Total deferred tax assets	420,376	390,042
Deferred tax liabilities:
Property, plant and equipment	(116,879)	(114,034)
All other items	(7,348)	(8,383)
Total deferred tax liabilities	(124,227)	(122,417)
Deferred Tax Assets, Net, Total	296,149	267,625
Valuation allowances	(27,993)	(28,271)
Net deferred tax asset	$ 268,156	$ 239,354