Income Taxes (Components Of Deferred Tax Assets And Liabilities) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax assets:
Employee benefits	$ 483	$ 585
Environmental	37	35
Other	49	55
Total deferred tax assets	569	675
Deferred tax liabilities:
Property, plant and equipment	2,290	2,225
Inventories	614	610
Investments in subsidiaries and affiliates	267	307
Other	70	29
Total deferred tax liabilities	3,241	3,171
Net deferred tax liabilities	$ 2,672	$ 2,496