XML 11 R3.htm IDEA: XBRL DOCUMENT v3.25.4

Investment Objectives and Goals	Dec. 31, 2025
MFS New Discovery Value Portfolio
Prospectus [Line Items]
Risk/Return [Heading]	MFS® New Discovery Value Portfolio

X

- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 1
-Subsection a

+ Details

Name:	oef_ProspectusLineItems
Namespace Prefix:	oef_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Section 2
-Name Form N-1A
-Subsection a

+ Details

Name:	oef_RiskReturnHeading
Namespace Prefix:	oef_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	dei_LegalEntityAxis=cik0001065698_S000023374Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: