XML 48 R28.htm IDEA: XBRL DOCUMENT
v3.21.1

Fair Value Measurements - Fair Value of Convertible Senior Notes (Details) - Senior Notes - USD ($) $ in Millions | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Fair Value Disclosures [Line Items] |  |
Fair value of outstanding senior convertible notes: | $ 3,075.7 | $ 3,155.6
Senior Convertible Notes due 2023 |  |
Fair Value Disclosures [Line Items] |  |
Fair value of outstanding senior convertible notes: | 1,879.1 | 1,936.4
Senior Convertible Notes due 2025 |  |
Fair Value Disclosures [Line Items] |  |
Fair value of outstanding senior convertible notes: | $ 1,196.6 | $ 1,219.2

X
- Definition [Line Items] for Fair Value Disclosures [Table] + References No definition available. + Details
Name: | dxcm_FairValueDisclosuresLineItems
Namespace Prefix: | dxcm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock. + References No definition available. + Details
Name: | us-gaap_ConvertibleDebtFairValueDisclosures
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dxcm_ConvertibleNotesDue2023Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=dxcm_ConvertibleNotesDue2025Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |