XML 49 R26.htm IDEA: XBRL DOCUMENT
v3.20.4

Employee Benefit Plans and Stockholders' Equity (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2020
Share-based Payment Arrangement [Abstract] |
Schedule of Intrinsic Value of Options Exercised and Fair Value of Options Vested | The total intrinsic value of stock options exercised as of the date of exercise was as follows:
| Twelve Months Ended December 31,
(In millions) | 2020 |  | 2019 |  | 2018
Intrinsic value of options exercised | $ | 7.9 |  |  | $ | 7.4 |  |  | $ | 30.0 |
Schedule of Restricted Stock Units Activity | A summary of our RSU activity for the twelve months ended December 31, 2020, 2019 and 2018 is as follows:
(In millions except weighted average grant date fair value) | Shares |  | Weighted Average Grant Date Fair Value |  | Aggregate Intrinsic Value
Nonvested at December 31, 2017 | 2.7 |  |  | $ | 70.68 |  |  |
Granted | 1.7 |  |  | 66.07 |  |  |
Vested | (1.4) |  |  | 68.44 |  |  |
Forfeited | (0.3) |  |  | 68.56 |  |  |
Nonvested at December 31, 2018 | 2.7 |  |  | 69.19 |  |  | $ | 319.0 |
Granted | 0.7 |  |  | 144.37 |  |  |
Vested | (1.4) |  |  | 69.45 |  |  |
Forfeited | (0.2) |  |  | 83.45 |  |  |
Nonvested at December 31, 2019 | 1.8 |  |  | 96.63 |  |  | 392.0 |
Granted | 0.5 |  |  | 300.36 |  |  |
Vested | (1.0) |  |  | 92.07 |  |  |
Forfeited | (0.1) |  |  | 137.44 |  |  |
Nonvested at December 31, 2020 | 1.2 |  |  | $ | 183.51 |  |  | $ | 430.6 |
Schedule of Stock Options Reserved for Future Issuance | Shares of common stock reserved for future issuance were as follows as of the dated indicated:
| December 31,
(In millions) | 2020 |  | 2019
Stock awards under our plans: |  |  |
Unvested restricted stock units | 1.2 |  |  | 1.8 |
Reserved for future grant | 4.5 |  |  | 4.9 |
Employee Stock Purchase Plan | 0.8 |  |  | 0.9 |
Total | 6.5 |  |  | 7.6 |
Schedule of Share-Based Compensation Expenses | The following table summarizes share-based compensation expense related to restricted stock units and employee stock purchases under the ESPP for the twelve months ended December 31, 2020, 2019 and 2018:
| Twelve Months Ended December 31,
(In millions) | 2020 |  | 2019 |  | 2018
Cost of sales | $ | 14.6 |  |  | $ | 9.0 |  |  | $ | 9.2 |
Research and development | 37.8 |  |  | 33.5 |  |  | 33.0 |
Selling, general and administrative | 67.0 |  |  | 60.2 |  |  | 59.7 |
Total share-based compensation expense | $ | 119.4 |  |  | $ | 102.7 |  |  | $ | 101.9 |
Schedule of Valuation Assumptions for Employee Stock Purchase Plan | We estimate the fair value of ESPP purchase rights on the date of grant using the Black-Scholes option pricing model and the assumptions below for the specified reporting periods.
| Twelve Months Ended December 31,
| 2020 |  | 2019 |  | 2018
Risk free interest rate | 0.13 - 0.95 |  | 1.72 - 2.55 |  | 1.55 - 2.25
Dividend yield | — | % |  | — | % |  | — | %
Expected volatility of Dexcom common stock | 0.51 - 0.63 |  | 0.40 - 0.51 |  | 0.50 - 0.67
Expected life (in years) | 0.5 |  | 1 |  | 1

X
- Definition Schedule of intrinsic value of options exercised and fair value of options vested table. + References No definition available. + Details
Name: | dxcm_ScheduleOfIntrinsicValueOfOptionsExercisedTableTableTextBlock
Namespace Prefix: | dxcm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of Shares Reserved For Future Issuance [Table Text Block] + References No definition available. + Details
Name: | dxcm_ScheduleOfSharesReservedForFutureIssuanceTableTableTextBlock
Namespace Prefix: | dxcm_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of allocation of amount expensed and capitalized for award under share-based payment arrangement to statement of income or comprehensive income and statement of financial position. Includes, but is not limited to, corresponding line item in financial statement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901 + Details
Name: | us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the changes in outstanding nonvested restricted stock units. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the significant assumptions used during the year to estimate the fair value of employee stock purchase plans, including, but not limited to: (a) expected term, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration