Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement [Abstract]
Revenue	$ 3,622.3	$ 2,909.8	$ 2,448.5
Cost of sales	1,333.4	1,026.7	768.0
Gross profit	2,288.9	1,883.1	1,680.5
Operating expenses:
Research and development	505.8	484.2	517.1
Collaborative research and development fee	0.0	0.0	87.1
Selling, general and administrative	1,185.4	1,007.7	810.5
Total operating expenses	1,691.2	1,491.9	1,414.7
Operating income	597.7	391.2	265.8
Other income (expense), net	112.7	(0.4)	(9.0)
Income before income taxes	710.4	390.8	256.8
Income tax expense	168.9	49.6	39.9
Net income	$ 541.5	$ 341.2	$ 216.9
Basic net income per share (in usd per share)	$ 1.40	$ 0.88	$ 0.56
Shares used to compute basic net income per share (in shares)	386.0	389.4	386.9
Diluted net income per share (in usd per share)	$ 1.30	$ 0.82	$ 0.53
Shares used to compute diluted net income per share (in shares)	425.5	427.5	428.8

Collaborative Research and Development Fee

No definition available.

Name:	dxcm_CollaborativeResearchAndDevelopmentFee
Namespace Prefix:	dxcm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.