Commitments and Contingencies - Commitments - Other (Details) $ in Millions	6 Months Ended
Jun. 30, 2022 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Construction and fit-out agreement, expected incurred costs	$ 17
Construction and fit-out agreement, lease term upon construction completion	2 years

Construction and Fit-out Agreement, Lease Term upon Construction Completion

No definition available.

Name:	ses_ConstructionAndFitOutAgreementLeaseTermUponConstructionCompletion
Namespace Prefix:	ses_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration