Contract Amounts of Foreign Exchange Contracts (Detail) (JPY ¥) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments and Hedging Activities Disclosure [Line Items]
To sell foreign currencies	¥ 391,455	¥ 466,361
To buy foreign currencies	¥ 75,016	¥ 48,686

Aggregate notional amount of foreign currency derivatives to purchase a foreign currency. Notional amount refers to the number of currency units specified in the foreign currency derivative contract.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5580258-113959

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5579245-113959

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