Change to previously reported depreciation and amortization.

No definition available.

Name:	cat_Changetopreviouslyreporteddepreciation
Namespace Prefix:	cat_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Sum of operating profit and nonoperating income or expense including restructuring costs before income or loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest

+ References

No definition available.

+ Details

Name:	cat_IncomeLossBeforeTaxesAfterRestructuringCosts
Namespace Prefix:	cat_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140864-122747

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_SubsegmentsConsolidationItemsAxis=us-gaap_ReportableSubsegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cat_ConstructionIndustriesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cat_ResourceIndustriesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cat_EnergyandTransportationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cat_FinancialProductsSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsegmentsConsolidationItemsAxis=cat_NonreportableSubsegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=cat_OtherSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Segment information (Details 4) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
Segment information (Details 4) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information
Change to previously reported depreciation				$ 58	$ 35
Consolidated profit before taxes			$ 139	3,439	3,152
Restructuring costs	$ (395)	$ (679)	(1,019)	(898)	(432)
Reportable segments
Segment Reporting Information
Consolidated profit before taxes			3,527	6,065	7,886
Reportable segments \| Construction Industries
Segment Reporting Information
Consolidated profit before taxes			1,650	1,865	2,133
Reportable segments \| Resource Industries
Segment Reporting Information
Consolidated profit before taxes			(1,047)	1	565
Reportable segments \| Energy & Transportation
Segment Reporting Information
Consolidated profit before taxes			2,222	3,390	4,287
Reportable segments \| Financial Products Segment
Segment Reporting Information
Consolidated profit before taxes			702	809	901
All Other operating segments
Segment Reporting Information
Consolidated profit before taxes			(77)	(75)	19
Business
Segment Reporting Information
Consolidated profit before taxes			3,450	5,990	7,905
Restructuring costs			(879)	(683)	425
Consolidated profit before taxes with restructuring costs			2,571	5,307	7,480
Business \| Reportable segments \| Construction Industries
Segment Reporting Information
Consolidated profit before taxes			1,650	1,865	2,133
Restructuring costs			(41)	(123)	(314)
Consolidated profit before taxes with restructuring costs			1,609	1,742	1,819
Business \| Reportable segments \| Resource Industries
Segment Reporting Information
Consolidated profit before taxes			(1,047)	1	565
Restructuring costs			(540)	(305)	(72)
Consolidated profit before taxes with restructuring costs			(1,587)	(304)	493
Business \| Reportable segments \| Energy & Transportation
Segment Reporting Information
Consolidated profit before taxes			2,222	3,390	4,287
Restructuring costs			(248)	(109)	(33)
Consolidated profit before taxes with restructuring costs			1,974	3,281	4,254
Business \| Reportable segments \| Financial Products Segment
Segment Reporting Information
Consolidated profit before taxes			702	809	901
Restructuring costs			(5)	(17)	0
Consolidated profit before taxes with restructuring costs			697	792	901
Business \| All Other operating segments \| All Other
Segment Reporting Information
Consolidated profit before taxes			(77)	(75)	19
Restructuring costs			(45)	(129)	(6)
Consolidated profit before taxes with restructuring costs			$ (122)	$ (204)	$ 13