Income Taxes - Schedule of components of deferred tax assets and liabilities (Parenthetical) (Details) $ in Millions	Dec. 31, 2020 USD ($)
Income Tax Disclosure [Abstract]
Net operating loss carryforwards deferred tax asset	$ 7.2
Accruals and reserves deferred tax asset	0.9
Deferred contract acquisition costs deferred tax liability	$ 8.1

Adjustment to increase the deferred contract acquisition costs deferred tax liability.

No definition available.

Name:	cflt_IncreaseInDeferredTaxLiabilitiesDeferredExpenseDeferredPolicyAcquisitionCost
Namespace Prefix:	cflt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant