The percentage of ownership acquired of common stock in an investee accounted for as available-for-sale securities.

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- Definition

Investment Percent Of Non-voting Rights Acquired

+ Details

Name:	erts_InvestmentPercentOfNonVotingRightsAcquired
Namespace Prefix:	erts
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of voting common shares available for conversion from preferred shares acquired.

+ Details

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Data Type:	us-types:percentItemType
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- Definition

The percentage of voting rights acquired of common stock in an investee accounted for as available-for-sale securities.

+ Details

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Namespace Prefix:	erts
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Payments To Acquire Non-Marketable Securities

+ Details

Name:	erts_PaymentsToAcquireNonMarketableSecurities
Namespace Prefix:	erts
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents the amount of gains and losses, including other than temporary impairments, recognized on strategic investments.

+ Details

Name:	erts_RealizedGainsLossesOnStrategicInvestments
Namespace Prefix:	erts
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 7, 26

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 8, 9

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 7
-Footnote 1

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 1
-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the total realized gain (loss) included in earnings for the period as a result of selling marketable securities categorized as trading, available-for-sale, or held-to-maturity. Additionally, this item would include any losses recognized for other than temporary impairments of the subject investments in debt and equity securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 16

+ Details

Name:	us-gaap_MarketableSecuritiesRealizedGainLoss
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow from purchases of trading, available-for-sale securities and held-to-maturity securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 15

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 17
-Subparagraph a

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 17
-Subparagraph b

+ Details

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Dividends received on equity and other investments during the current period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 27

+ Details

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

- Definition

The cash inflow associated with the sale of equity securities classified as available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 18

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 15

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 16
-Subparagraph b

+ Details

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

Financial Instruments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended						12 Months Ended				1 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended		1 Months Ended		12 Months Ended	1 Months Ended	12 Months Ended	1 Months Ended
	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2009	Jun. 30, 2009	Mar. 31, 2011	Mar. 31, 2010	Mar. 31, 2009	Mar. 31, 2008	May 31, 2007 The9 [Member]	Mar. 31, 2011 The9 [Member]	Mar. 31, 2010 The9 [Member]	Mar. 31, 2009 The9 [Member]	Feb. 28, 2005 Ubisoft [Member]	Mar. 31, 2011 Ubisoft [Member]	Mar. 31, 2010 Ubisoft [Member]	Apr. 30, 2008 Neowiz [Member]	Apr. 30, 2007 Neowiz [Member] Common Stock [Member]	Mar. 31, 2009 Neowiz [Member] Common Stock [Member]	Apr. 30, 2007 Neowiz [Member] Preferred Shares [Member]	Mar. 31, 2009 Neowiz [Member] Preferred Shares [Member]	Apr. 30, 2007 Neowiz Corporation [Member] Common Stock [Member]	Apr. 30, 2007 Neowiz Games [Member] Common Stock [Member]
Cash and cash equivalents			$ 1,273				$ 1,579	$ 1,273	$ 1,621	$ 1,553
Purchase price of investment											167				91				83
Gains (losses) on strategic investments, net	28	(5)	(1)	(1)	(8)	(16)	23	(26)	(62)			2	26	27						30		10
Percentage of outstanding shares											15.00%				19.90%		15.00%						15.00%	15.00%
Voting rights acquired											15.00%				18.00%		13.00%						15.00%	15.00%
Preferred shares convertible option voting rights																		4.00%
Non-voting rights acquired																					100.00%
Purchase price of preferred shares																					27
Proceeds from sale of marketable equity securities							132	17	0			11	17			121
Gain/(loss) on sale of marketable equity securities												(3)	(1)			28
Cash dividend received														$ 5