Fair value measurements (Details 2) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010
Fair Value Assets and Fair Value Liabilities Measured on Recurring Basis Unobservable Input Reconciliation Asset and Liability [Line Items]
Level 3 measurement reconciliation, recurring basis, fair value assets beginning balance	$ 23	$ 84
Total gains or (losses) (realized/unrealized) included in investment and other income, net		0
Purchases or acquired sales, issuances and settlements		(61)
Level 3 measurement reconciliation, recurring basis, fair value assets ending balance	25	23
Total gains or (losses) (realized/unrealized) Included in other comprehensive loss	2
Fair Value Assets and Fair Value Liabilities Measured on Recurring Basis Unobservable Input Reconciliation Asset and Liability
The amount of total gains or (losses) for the period included in investment and other income, net attributable to the change in unrealized gains or losses relating to assets and liabilities still held at September 30, 2010		0
Percentage of assets measured on recurring basis at fair value using significant unobservable inputs (in hundredths)	1.00%
ARS
Fair Value Assets and Fair Value Liabilities Measured on Recurring Basis Unobservable Input Reconciliation Asset and Liability [Line Items]
Level 3 measurement reconciliation, recurring basis, fair value assets beginning balance	23	77
Total gains or (losses) (realized/unrealized) included in investment and other income, net		7
Purchases or acquired sales, issuances and settlements		(61)
Level 3 measurement reconciliation, recurring basis, fair value assets ending balance	25	23
Total gains or (losses) (realized/unrealized) Included in other comprehensive loss	2
Fair Value Assets and Fair Value Liabilities Measured on Recurring Basis Unobservable Input Reconciliation Asset and Liability
The amount of total gains or (losses) for the period included in investment and other income, net attributable to the change in unrealized gains or losses relating to assets and liabilities still held at September 30, 2010		0
ARS rights from UBS
Fair Value Assets and Fair Value Liabilities Measured on Recurring Basis Unobservable Input Reconciliation Asset and Liability [Line Items]
Level 3 measurement reconciliation, recurring basis, fair value assets beginning balance		7
Total gains or (losses) (realized/unrealized) included in investment and other income, net		(7)
Purchases or acquired sales, issuances and settlements		0
Level 3 measurement reconciliation, recurring basis, fair value assets ending balance		0
Fair Value Assets and Fair Value Liabilities Measured on Recurring Basis Unobservable Input Reconciliation Asset and Liability
The amount of total gains or (losses) for the period included in investment and other income, net attributable to the change in unrealized gains or losses relating to assets and liabilities still held at September 30, 2010		0
Other financial liabilities
Fair Value Assets and Fair Value Liabilities Measured on Recurring Basis Unobservable Input Reconciliation Asset and Liability [Line Items]
Level 3 measurement reconciliation, recurring basis, fair value assets beginning balance		(23)
Total gains or (losses) (realized/unrealized) included in investment and other income, net		13
Purchases or acquired sales, issuances and settlements		0
Level 3 measurement reconciliation, recurring basis, fair value assets ending balance		(10)
Fair Value Assets and Fair Value Liabilities Measured on Recurring Basis Unobservable Input Reconciliation Asset and Liability
The amount of total gains or (losses) for the period included in investment and other income, net attributable to the change in unrealized gains or losses relating to assets and liabilities still held at September 30, 2010		$ 13

Name:	atvi_FairValueAssetsAndFairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationAssetAndLiabilityLineItems
Namespace Prefix:	atvi
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

This item represents the amount of the total change in unrealized (holding) gains or losses for the period which are included in the statement of income. Such unrealized (holding) gains or losses relate to those assets still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

+ Details

Name:	atvi_FairValueAssetsStillHeldMeasuredOnRecurringBasisChangeInUnrealizedGainLossIncludedInEarnings
Namespace Prefix:	atvi
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents purchases, sales, issuances, and settlements (net) which have taken place during the period in relation to assets and liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3).

+ Details

Name:	atvi_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetsAndLiabilitiesPurchasesSalesIssuancesSettlements
Namespace Prefix:	atvi
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents percentage of assets measured on recurring basis at fair value using significant unobservable Inputs.

+ Details

Name:	atvi_PercentageOfAssetsMeasuredOnRecurringBasisAtFairValueUsingSignificantUnobservableInputs
Namespace Prefix:	atvi
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ Details

Name:	us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c(1)

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c(1)

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncome
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant