Commitments and Contingencies - Legal Matters (Details)		12 Months Ended
Dec. 31, 2011 USD ($)	Dec. 31, 2011 Hitachi Complaint Filed in July 2010 [Member] JPY (¥)	Dec. 31, 2011 Hitachi Complaint Filed in September 2010 [Member] JPY (¥)	Dec. 31, 2011 Hitachi Complaint Filed in August 2011 [Member] JPY (¥)
Loss Contingencies [Line Items]
Litigation damages sought		¥ 2,500,000,000	¥ 1,300,000,000	¥ 2,800,000,000
Accrual for contingent litigation	$ 5,300,000

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

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

-Publisher FASB

-Name Accounting Standards Codification

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-Name Statement of Financial Accounting Standard (FAS)

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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