Income Tax (Details 1) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Components of Net Deferred Tax Assets
Postretirement benefits, net	$ 412	$ 440
Intangible assets	(1,471)	(1,498)
Investments in non-US Subsidiaries	(348)	(349)
Other, net	145	132
Net deferred tax assets	$ (1,262)	$ (1,275)

The tax effect as of the balance sheet date of the amount of the estimated future tax reductions attributable to a difference between the tax basis and the generally accepted accounting principles basis of a company's investment in its wholly-owned subsidiaries which will decrease future taxable income when such basis difference reverses.

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The tax effect as of the balance sheet date of the amount of estimated future tax deductions arising from other temporary differences not otherwise specified in the taxonomy.

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- Definition

The tax effect as of the balance sheet date of the amount of estimated future tax deductions arising from postretirement benefits, which can only be deducted for tax purposes when actual costs are incurred, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deduction to be taken.

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