Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Earnings per share

Earnings Per Share Computations

(Amounts in millions, except per share amounts)	2015		2014		2013
Numerator:
Net income attributable to 3M	$	4,833	$	4,956	$	4,659
Denominator:
Denominator for weighted average 3M common shares outstanding — basic		625.6		649.2		681.9
Dilution associated with the Company’s stock-based compensation plans		11.6		12.8		11.7
Denominator for weighted average 3M common shares outstanding — diluted		637.2		662.0		693.6
Earnings per share attributable to 3M common shareholders — basic	$	7.72	$	7.63	$	6.83
Earnings per share attributable to 3M common shareholders — diluted	$	7.58	$	7.49	$	6.72

Change in accounting principle marketable securities

Impact on previously reported values after accounting change

	December 31, 2014
(Millions)	Previously Reported		Impact		As Adjusted
Marketable securities - current	$	626	$	813	$	1,439
Marketable securities - non-current		828		(813)		15
Total marketable securities	$	1,454	$	—	$	1,454

Deferred tax assets and deferred tax liabilities impact on accounting change adoption

Impact on previously reported values after accounting change

	December 31, 2014
(Millions)	Previously Reported		Impact		As Adopted
Prepaid expenses and other (within other current assets)	$	595	$	169	$	764
Other current tax assets (within other current assets)		444		(444)		—
Deferred tax assets (within other assets)		889		241		1,130
Deferred tax liabilities (within other current liabilities)		34		(34)		—