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, 2012 Customer relationship Y	Mar. 31, 2012 Trademarks Y	Mar. 31, 2012 Other Y	Feb. 15, 2012 Sony Ericsson	Feb. 15, 2012 Sony Ericsson IP cross-licensing Y	Feb. 15, 2012 Sony Ericsson Developed technology Y	Feb. 15, 2012 Sony Ericsson Customer relationship Y	Feb. 15, 2012 Sony Ericsson Trademarks Y	Feb. 15, 2012 Sony Ericsson Other Y
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	14	7	4		6	9	14	7	7

The calculated weighted-average amortization period of a major class of finite-lived intangible assets acquired during the current period either individually or as part of a group of assets (in either an asset acquisition or business combination). A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 44

-Subparagraph a(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16265-109275

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration