Loss Contingencies, Patents Allegedly Infringed, Number of inter partes reviews requested

No definition available.

Name:	dxcm_LossContingenciesPatentsAllegedlyInfringedNumberofinterpartesreviewrequested
Namespace Prefix:	dxcm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Loss Contingency, Patents Allegedly Infringed, Number Transferred to New Plaintiff

+ References

No definition available.

+ Details

Name:	dxcm_LossContingencyPatentsAllegedlyInfringedNumberTransferredtoNewPlaintiff
Namespace Prefix:	dxcm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of entity's patents that another entity has allegedly infringed.

+ References

No definition available.

+ Details

Name:	us-gaap_GainContingencyPatentsAllegedlyInfringedUponNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate carrying amount of the estimated litigation liability for known or estimated probable loss from litigation, which may include attorneys' fees and other litigation costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.25)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LitigationReserve
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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

- Definition

Amount of loss contingency liability.

+ References

+ Details

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of another entity's patents that the entity has allegedly infringed.

+ References

No definition available.

+ Details

Name:	us-gaap_LossContingencyPatentsAllegedlyInfringedNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dxcm_NameofPlaintiffAxis=dxcm_AgaMatrixMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dxcm_NameofPlaintiffAxis=dxcm_WaveFormTechnologiesInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dxcm_NameofDefendantAxis=dxcm_AgaMatrixMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments and Contingencies Litigation (Details)	Mar. 30, 2018 number_patents	Feb. 28, 2018 number_patents	Sep. 15, 2017 number_patents	Mar. 08, 2017 number_patents	Feb. 24, 2017 number_patents	Aug. 25, 2016 number_patents	Jun. 06, 2016 number_patents	Sep. 30, 2018 USD ($)
Loss Contingencies [Line Items]
Loss contingency accrual \| $								$ 0
Estimated litigation liability \| $								$ 0
AgaMatrix
Loss Contingencies [Line Items]
Loss contingency, patents allegedly infringed, number							3
WaveForm Technologies, Inc.
Loss Contingencies [Line Items]
Loss contingency, patents allegedly infringed, number transferred to new plaintiff					3
Loss contingencies, patents allegedly infringed, number of inter partes review requested	2	2		3		2
AgaMatrix
Loss Contingencies [Line Items]
Gain contingency, patents allegedly infringed upon, number			2