Supplemental Equity and Comprehensive Income Information (Details 4) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Components of Comprehensive Income (Loss) Attributable to 3M
Net income attributable to 3M	$ 1,160	$ 1,121	$ 2,241	$ 2,051
Cumulative translation	205	(324)	426	(401)
Tax effect	20	(46)	47	(63)
Cumulative translation - net of tax	225	(370)	473	(464)
Defined benefit pension and postretirement plans adjustment	119	80	238	156
Tax effect	(66)	(32)	(109)	(58)
Defined benefit pension and postretirement plans adjustment - net of tax	53	48	129	98
Debt and equity securities, unrealized gain (loss)	(3)	1	(5)	4
Tax effect	1		2	(2)
Debt and equity securities, unrealized gain (loss) - net of tax	(2)	1	(3)	2
Cash flow hedging instruments, unrealized gain (loss)	1	64	(26)	100
Tax effect	(1)	(24)	9	(37)
Cash flow hedging instruments, unrealized gain (loss) - net of tax		40	(17)	63
Total Comprehensive income (loss) attributable to 3M	1,436	840	2,823	1,750
Reclassification to earnings from accumulated other comprehensive income including noncontrolling interest that related to pension and postretirement expense in the income statement, before tax	119	78	238	154
Reclassification to earnings from accumulated other comprehensive income including noncontrolling interest that related to pension and postretirement expense in the income statement, after tax	$ 54	$ 48	$ 130	$ 99