Segment information (Details 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	$ 4,082	$ 139	$ 3,439
Reportable segments
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	7,623	3,527	6,065
All Other operating segments
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(43)	(77)	(75)
Cost Centers
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	22	8	20
Corporate Costs
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(633)	(527)	(600)
Timing
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(151)	40	95
Restructuring Costs
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(1,256)	(1,019)	(898)
Inventory/cost of sales
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(77)	0	(100)
Postretirement Benefits Expense
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(165)	(788)	131
Stock-Based Compensation Expense
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(206)	(218)	(283)
Financing Costs
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(524)	(517)	(524)
Currency
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(218)	(22)	(261)
Other Income Expense Methodology Differences
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(181)	(225)	(95)
Other
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(109)	(43)	(36)
Business
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	7,580	3,450	5,990
Machinery, Energy & Transportation | Reportable segments
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	6,831	2,825	5,256
Machinery, Energy & Transportation | Business
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	3,314	(553)	2,617
Machinery, Energy & Transportation | Business | Reportable segments
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	6,831	2,825	5,256
Machinery, Energy & Transportation | Business | All Other operating segments
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(43)	(77)	(75)
Machinery, Energy & Transportation | Business | Cost Centers
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	22	8	20
Machinery, Energy & Transportation | Business | Corporate Costs
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(633)	(527)	(600)
Machinery, Energy & Transportation | Business | Timing
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(151)	40	95
Machinery, Energy & Transportation | Business | Restructuring Costs
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(1,253)	(1,014)	(881)
Machinery, Energy & Transportation | Business | Inventory/cost of sales
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(77)	0	(100)
Machinery, Energy & Transportation | Business | Postretirement Benefits Expense
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(165)	(788)	131
Machinery, Energy & Transportation | Business | Stock-Based Compensation Expense
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(198)	(209)	(270)
Machinery, Energy & Transportation | Business | Financing Costs
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(524)	(517)	(524)
Machinery, Energy & Transportation | Business | Currency
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(218)	(22)	(261)
Machinery, Energy & Transportation | Business | Other Income Expense Methodology Differences
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(181)	(225)	(95)
Machinery, Energy & Transportation | Business | Other
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(96)	(47)	(79)
Financial Products | Business
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	768	692	822
Financial Products | Business | Reportable segments
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	792	702	809
Financial Products | Business | All Other operating segments
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	0	0	0
Financial Products | Business | Cost Centers
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	0	0	0
Financial Products | Business | Corporate Costs
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	0	0	0
Financial Products | Business | Timing
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	0	0	0
Financial Products | Business | Restructuring Costs
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(3)	(5)	(17)
Financial Products | Business | Inventory/cost of sales
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	0	0	0
Financial Products | Business | Postretirement Benefits Expense
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	0	0	0
Financial Products | Business | Stock-Based Compensation Expense
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	(8)	(9)	(13)
Financial Products | Business | Financing Costs
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	0	0	0
Financial Products | Business | Currency
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	0	0	0
Financial Products | Business | Other Income Expense Methodology Differences
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	0	0	0
Financial Products | Business | Other
Reconciliation of Consolidated profit (loss) before taxes
Consolidated profit before taxes	$ (13)	$ 4	$ 43