CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - USD ($) $ in Millions		Total IBM Stockholders' Equity	Common Stock and Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income/(Loss)	Non-Controlling Interests	Total
Balance at the Beginning of the Period at Dec. 31, 2015		$ 14,262	$ 53,262	$ 146,124	$ (155,518)	$ (29,607)	$ 162	$ 14,424
Equity
Net income		7,371		7,371				7,371
Other comprehensive income/(loss)		1,442				1,442		1,442
Total comprehensive income/(loss)		8,813						8,813
Cash dividends paid - common stock		(3,927)		(3,927)				(3,927)
Common stock issued under employee plans (Shares - 3,372,586 and 3,370,992 for the nine months ended September 30, 2017 and 2016 respectively)		513	513					513
Purchases (Shares - 960,186 and 787,805) and sales (Shares - 363,335 and 336,480) of treasury stock under employee plans - net, for the nine months ended September 30, 2017 and 2016 respectively		(56)		16	(72)			(56)
Other treasury shares purchased, not retired (Shares - 22,851,760 and 17,793,841 for the nine months ended September 30, 2017 and 2016 respectively)		(2,579)			(2,579)			(2,579)
Changes in other equity		(17)	(16)	0				(17)
Changes in noncontrolling interests							(12)	(12)
Balance at the End of the Period at Sep. 30, 2016		17,010	53,759	149,585	(158,170)	(28,164)	149	17,159
Balance at the Beginning of the Period at Dec. 31, 2016		18,246	53,935	152,759	(159,050)	(29,398)	146	18,392
Equity
Cumulative effect of change in accounting principle	[1]	102		102				102
Net income		6,807		6,807				6,807
Other comprehensive income/(loss)		1,877				1,877		1,877
Total comprehensive income/(loss)		8,684						8,684
Cash dividends paid - common stock		(4,119)		(4,119)				(4,119)
Common stock issued under employee plans (Shares - 3,372,586 and 3,370,992 for the nine months ended September 30, 2017 and 2016 respectively)		460	460					460
Purchases (Shares - 960,186 and 787,805) and sales (Shares - 363,335 and 336,480) of treasury stock under employee plans - net, for the nine months ended September 30, 2017 and 2016 respectively		(91)		15	(106)			(91)
Other treasury shares purchased, not retired (Shares - 22,851,760 and 17,793,841 for the nine months ended September 30, 2017 and 2016 respectively)		(3,655)			(3,655)			(3,655)
Changes in noncontrolling interests							(16)	(16)
Balance at the End of the Period at Sep. 30, 2017		$ 19,627	$ 54,395	$ 155,565	$ (162,812)	$ (27,521)	$ 130	$ 19,757

[1] Reflects the adoption of the FASB guidance on intra-entity transfers of assets in the first-quarter 2017.