Label	Element	Value
Prospectus:	rr_ProspectusTable
Document Type	dei_DocumentType	Other
Document Period End Date	dei_DocumentPeriodEndDate	Dec. 31, 2014
Registrant Name	dei_EntityRegistrantName	Calvert Variable Series Inc
Central Index Key	dei_EntityCentralIndexKey	0000708950
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Oct. 01, 2015
Document Effective Date	dei_DocumentEffectiveDate	Oct. 01, 2015
Prospectus Date	rr_ProspectusDate	Apr. 30, 2015
Calvert VP SRI Balanced Portfolio Series \| Class I
Prospectus:	rr_ProspectusTable
Supplement [Text Block]	cik0000708950_SupplementTextBlock	CALVERT VP SRI BALANCED PORTFOLIO CALVERT VP SRI LARGE CAP VALUE PORTFOLIO Supplement to Calvert Variable Products Prospectus (Calvert VP SRI Portfolios) dated April 30, 2015 Date of Supplement: October 1, 2015 Effective immediately, Calvert VP SRI Balanced Portfolio and Calvert VP SRI Large Cap Value Portfolio (each a “Portfolio”) have adopted the Calvert Principles for Responsible Investment. Furthermore, effective November 16, 2015, Calvert VP SRI Balanced Portfolio has approved the addition of certain portfolio managers for the fixed-income assets of the Portfolio to better reflect a team approach to portfolio management. Responsible Investment Principles Effective immediately, each Prospectus is hereby amended as follows:
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The last two paragraphs under “Investments, Risks and Performance – Principal Investment Strategies” in the Portfolio Summary for each Portfolio is deleted and replaced with the following: Responsible Investing. In conjunction with Calvert’s financial analysis, Calvert’s comprehensive responsible investment principles guide our investment research processes and decision-making. The principles are applied across industries and to specific companies in order to inform our view of risk and opportunity factors that may affect investment performance.
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	Under "Investments, Risks and Performance – Principal Risks” in the Portfolio Summary for each Portfolio, delete “Sustainable and Socially Responsible Investing Risk" and insert the following: Responsible Investing Risk. Investing primarily in responsible investments carries the risk that, under certain market conditions, the Portfolio may underperform funds that invest in a broader array of investments. The application of responsible investment principles may affect the Portfolio’s exposure to certain sectors or types of investments and may impact the Portfolio’s relative investment performance, depending on whether such sectors or investments are in or out of favor in the market.

Label

Element

Value

Prospectus:

rr_ProspectusTable

Document Type

dei_DocumentType

Other

Document Period End Date

dei_DocumentPeriodEndDate

Dec. 31, 2014

Registrant Name

dei_EntityRegistrantName

Calvert Variable Series Inc

Central Index Key

dei_EntityCentralIndexKey

0000708950

Amendment Flag

dei_AmendmentFlag

false

Document Creation Date

dei_DocumentCreationDate

Oct. 01, 2015

Document Effective Date

dei_DocumentEffectiveDate

Oct. 01, 2015

Prospectus Date

rr_ProspectusDate

Apr. 30, 2015

Calvert VP SRI Balanced Portfolio Series | Class I

Prospectus:

rr_ProspectusTable

Supplement [Text Block]

cik0000708950_SupplementTextBlock

CALVERT VP SRI BALANCED PORTFOLIO

CALVERT VP SRI LARGE CAP VALUE PORTFOLIO

Supplement to

Calvert Variable Products Prospectus (Calvert VP SRI Portfolios)

dated April 30, 2015

Date of Supplement: October 1, 2015

Effective immediately, Calvert VP SRI Balanced Portfolio and Calvert VP SRI Large Cap Value Portfolio (each a “Portfolio”) have adopted the Calvert Principles for Responsible Investment. Furthermore, effective November 16, 2015, Calvert VP SRI Balanced Portfolio has approved the addition of certain portfolio managers for the fixed-income assets of the Portfolio to better reflect a team approach to portfolio management.

Responsible Investment Principles

Effective immediately, each Prospectus is hereby amended as follows:

Strategy Narrative [Text Block]

rr_StrategyNarrativeTextBlock

The last two paragraphs under “Investments, Risks and Performance – Principal Investment Strategies” in the Portfolio Summary for each Portfolio is deleted and replaced with the following:

Responsible Investing. In conjunction with Calvert’s financial analysis, Calvert’s comprehensive responsible investment principles guide our investment research processes and decision-making. The principles are applied across industries and to specific companies in order to inform our view of risk and opportunity factors that may affect investment performance.

Risk Narrative [Text Block]

rr_RiskNarrativeTextBlock

Under "Investments, Risks and Performance – Principal Risks” in the Portfolio Summary for each Portfolio, delete “Sustainable and Socially Responsible Investing Risk" and insert the following:

Responsible Investing Risk. Investing primarily in responsible investments carries the risk that, under certain market conditions, the Portfolio may underperform funds that invest in a broader array of investments. The application of responsible investment principles may affect the Portfolio’s exposure to certain sectors or types of investments and may impact the Portfolio’s relative investment performance, depending on whether such sectors or investments are in or out of favor in the market.