Commitments and Contingencies - Other (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2025	Dec. 31, 2024
Commitments and Contingencies.
Restricted cash pledged for letter of credit	$ 3.8	$ 4.7
Adjustment rate of Letter of Credit (as a percent)	20.00%
Amount of Letter of Credit outstanding after adjustments	$ 2.0
Deferred compensation plan
Deferred compensation plan liability	17.3	14.6
Deferred compensation plan assets	$ 17.2	$ 14.7

Represents the adjustment percentage to the letters of credit balance outstanding.

No definition available.

Name:	gkos_AdjustmentPercentageOfLettersOfCreditBalanceOutstanding
Namespace Prefix:	gkos_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the minimal amount of letters of credit balance outstanding after all adjustments.

+ References

No definition available.

+ Details

Name:	gkos_MinimalAmountOfLettersOfCreditBalanceOutstandingAfterAdjustments
Namespace Prefix:	gkos_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the amount of restricted cash pledged for letter of credit.

+ References

No definition available.

+ Details

Name:	gkos_RestrictedCashPledgedForLetterOfCredit
Namespace Prefix:	gkos_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable beyond one year (or the operating cycle, if longer).

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_DeferredCompensationPlanAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant