Description of Business, Basis of Financial Statement Presentation and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Mar. 31, 2011

Description of Business Basis of Financial Statement Presentation and Summary of Significant Accounting Policies Tables [Abstract]

Effective rates of depreciation for buildings, machinery and equipment

	2011			2010			2009
Buildings		9	%		9	%		9	%
Machinery and equipment		23	%		23	%		25	%

Aggregate Cost of Property Plant and Equipment and Related Accumulated Amortization [Text Block]

					Thousands of
	Millions of yen				U.S. dollars
	2011		2010		2011
Aggregate cost	¥	83,436	¥	136,171	$	1,005,253
Accumulated amortization		36,331		49,512		437,723