INCOME TAXES - Items Included in Our Deferred Income Tax Assets (Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Postretirement benefits	$ 144	$ 134
Pension	521	337
Real estate impairments	115	141
State tax credits	59	57
Net operating loss carryforwards	187	162
Cellulosic biofuel producers credit	240	240
Other	336	369
Gross deferred tax assets	1,602	1,440
Valuation allowance	(144)	(139)
Net deferred tax assets	1,458	1,301
Property, plant and equipment	(577)	(610)
Timber installment notes	(240)	(277)
Other	(185)	(186)
Deferred tax liabilities	(1,002)	(1,073)
Net deferred tax assets	$ 456	$ 228