Liability For Pension and Other Retirement Benefits (Details 12) (Other Postretirement Benefit Plans, Defined Benefit [Member]) In Thousands	12 Months Ended
Mar. 31, 2011 USD ($)	Mar. 31, 2011 JPY (¥)
Amortized estimated actuarial loss and prior service cost from accumulated other comprehensive income loss into net periodic cost over the next fiscal year
Actuarial loss	$ 2,096	¥ 174,000
Prior service cost	$ 783	¥ 65,000

The amounts in accumulated other comprehensive income related to gains and losses that are not recognized immediately and are expected to be recognized as components of net periodic benefit cost over the next fiscal year that follows the most recent annual statement of financial position presented.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph s

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 158
-Paragraph 7
-Subparagraph d

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