Consolidated Statement of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net income including noncontrolling interest	$ 4,998us-gaap_ProfitLoss	$ 4,721us-gaap_ProfitLoss	$ 4,511us-gaap_ProfitLoss
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(942)	(505)	71
Defined benefit pension and postretirement plans adjustment	(1,562)	1,245	201
Debt and equity securities - unrealized gain (loss)	2	0	4
Cash flow hedging instruments - unrealized gain (loss)	107	15	(45)
Total other comprehensive income (loss), net of tax	(2,395)	755	231
Comprehensive income (loss) including noncontrolling interest	2,603	5,476	4,742
Comprehensive (income) loss attributable to noncontrolling interest	(48)	20	(23)
Comprehensive income (loss) attributable to 3M	$ 2,555us-gaap_ComprehensiveIncomeNetOfTax	$ 5,496us-gaap_ComprehensiveIncomeNetOfTax	$ 4,719us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax and reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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