Lessee, Operating Lease, Abatement Period

No definition available.

Name:	seer_LesseeOperatingLeaseAbatementPeriod
Namespace Prefix:	seer_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Operating Lease, Annual Lease Base Rent Increase (Decrease)

+ References

No definition available.

+ Details

Name:	seer_OperatingLeaseAnnualLeaseBaseRentIncreaseDecrease
Namespace Prefix:	seer_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Operating Lease, Lease Income, Lease Payment at End of Term

+ References

No definition available.

+ Details

Name:	seer_OperatingLeaseLeaseIncomeLeasePaymentAtEndOfTerm
Namespace Prefix:	seer_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Operating Lease, Lease Income, Lease Payments, Tenant Incentives

+ References

No definition available.

+ Details

Name:	seer_OperatingLeaseLeaseIncomeLeasePaymentsTenantIncentives
Namespace Prefix:	seer_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918673-209980

+ Details

Name:	us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Term of lessor's operating lease renewal for lease not yet commenced, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=121576215&loc=SL77919359-209981

+ Details

Name:	us-gaap_LessorOperatingLeaseLeaseNotYetCommencedRenewalTerm1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121573735&loc=d3e41499-112717

+ Details

Name:	us-gaap_OperatingLeasesRentExpenseNet
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

No definition available.

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=seer_FacilityLeaseAgreementLetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Commitments - Facility Lease Agreement Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Other Commitments [Line Items]
Not yet commenced, renewal term	127 months 15 days
Annual base rent	$ 0.9
Abatement period	9 months
Lease payments, annual increase, final year total	$ 1.2
Tenant incentives	$ 2.4
Current renewal term	5 years
Rent expense		$ 0.2	$ 0.2
Facility Lease Agreement Letter of Credit \| Letter of Credit
Other Commitments [Line Items]
Letter of credit issued				$ 0.3