Consolidated Statement of Income (USD $)
In Millions, except Per Share data, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Net sales $ 7,578 $ 7,831
Operating expenses    
Cost of sales 3,821 4,031
Selling, general and administrative expenses 1,564 1,632
Research, development and related expenses 463 452
Total operating expenses 5,848 6,115
Operating income 1,730 1,716
Interest expense and income    
Interest expense 31 37
Interest income (4) (9)
Total interest expense - net 27 28
Income before income taxes 1,703 1,688
Provision for income taxes 502 463
Net income including noncontrolling interest 1,201 1,225
Less: Net income attributable to noncontrolling interest 2 18
Net income attributable to 3M $ 1,199 $ 1,207
Weighted average 3M common shares outstanding - basic (in shares) 636.2 661.5
Earnings per share attributable to 3M common shareholders - basic (in dollars per share) $ 1.88 $ 1.83
Weighted average 3M common shares outstanding - diluted (in shares) 649.2 674.5
Earnings per share attributable to 3M common shareholders - diluted (in dollars per share) $ 1.85 $ 1.79
Cash dividends paid per 3M common share (in dollars per share) $ 1.025 $ 0.855