Supplemental Equity and Comprehensive Income Information (Details 4) (USD $) In Millions	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Components of Comprehensive Income (Loss) Attributable to 3M
Net income attributable to 3M	$ 1,088	$ 1,106	$ 3,329	$ 3,157
Cumulative translation	(489)	586	(63)	185
Tax effect	(18)	65	29	2
Cumulative translation - net of tax	(507)	651	(34)	187
Defined benefit pension and postretirement plans adjustment	120	75	358	231
Tax effect	(43)	(27)	(152)	(85)
Defined benefit pension and postretirement plans adjustment - net of tax	77	48	206	146
Debt and equity securities, unrealized gain (loss)	(3)	3	(8)	7
Tax effect	1		3	(2)
Debt and equity securities, unrealized gain (loss) - net of tax	(2)	3	(5)	5
Cash flow hedging instruments, unrealized gain (loss)	85	(84)	59	16
Tax effect	(31)	32	(22)	(5)
Cash flow hedging instruments, unrealized gain (loss) - net of tax	54	(52)	37	11
Total Comprehensive income (loss) attributable to 3M	710	1,756	3,533	3,506
Reclassification to earnings from accumulated other comprehensive income including noncontrolling interest that related to pension and postretirement expense in the income statement, before tax	117	77	355	231
Reclassification to earnings from accumulated other comprehensive income including noncontrolling interest that related to pension and postretirement expense in the income statement, after tax	$ 77	$ 48	$ 207	$ 147

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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