SHARE-BASED COMPENSATION - Stock-Based Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	$ 212.8	$ 199.9	$ 426.1	$ 389.6
Income tax benefit	43.0	39.3	85.7	76.3
Share-based compensation expense after income taxes	169.8	160.6	340.4	313.3
Cost of revenue – product \| Amounts capitalized into inventory
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	(32.9)	(31.3)	(67.8)	(59.8)
Location, Statement of Income, Balance: us-gaap:ResearchAndDevelopmentExpense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	86.7	74.7	168.7	143.7
Location, Statement of Income, Balance: us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	38.0	38.9	76.6	77.3
Location, Statement of Income, Balance: us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax \| Cost of revenue – product
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	28.8	30.3	58.1	60.5
Location, Statement of Income, Balance: us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax \| Cost of revenue – service
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	9.2	8.6	18.5	16.8
Location, Statement of Income, Balance: us-gaap:SellingGeneralAndAdministrativeExpense
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense before income taxes	$ 88.1	$ 86.3	$ 180.8	$ 168.6

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section S45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479983/718-10-S45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479830/718-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

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

- Definition

Amount, after tax, of expense for award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

Name:	us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax
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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

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

- Definition

Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

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

- Details

Name:	isrg_ConsolidatingReportingAxis=isrg_CostOfSalesProductMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	isrg_CostOfSalesProductsAxis=isrg_CapitalizedIntoInventoryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementOfIncomeLocationBalanceAxis=us-gaap_ResearchAndDevelopmentExpense
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementOfIncomeLocationBalanceAxis=us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	isrg_ConsolidatingReportingAxis=isrg_CostOfSalesServiceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementOfIncomeLocationBalanceAxis=us-gaap_SellingGeneralAndAdministrativeExpense
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: