Fair Value and Weighted-Average Amortization of Intangible Assets in Connection with Sony Mobile Communications Segment (Detail) (JPY ¥) In Millions, unless otherwise specified	12 Months Ended		1 Months Ended
Mar. 31, 2013 Trademarks	Mar. 31, 2013 Other	Feb. 15, 2012 Sony Ericsson	Feb. 15, 2012 Sony Ericsson IP cross-licensing	Feb. 15, 2012 Sony Ericsson Developed technology	Feb. 15, 2012 Sony Ericsson Customer relationship	Feb. 15, 2012 Sony Ericsson Trademarks	Feb. 15, 2012 Sony Ericsson Other
Business Acquisition [Line Items]
Acquired intangibles recorded at fair value, subject to amortization			¥ 123,097	¥ 60,834	¥ 24,599	¥ 19,597	¥ 14,086	¥ 3,981
Weighted-average amortization period	10 years	4 years		6 years	9 years	14 years	7 years	7 years

The amount of acquisition cost of a business combination allocated to an identifiable intangible asset that will be amortized.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 51

-Subparagraph e

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 52

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_BusinessAcquisitionPurchasePriceAllocationAmortizableIntangibleAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant