Long-Term Debt (Detail) (JPY ¥) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Debt Outstanding [Line Items]
Loans, principally from banks, maturing in installments through 2020; bearing weighted average interest of 1.68% and 1.83% at December 31, 2011 and 2010, respectively	¥ 1,297	¥ 1,013
Capital lease obligations	4,597	8,247
Long-term debt, including current installments	7,070	9,260
Less current portion	(3,702)	(5,129)
Long-term debt, excluding current installments (Note 9)	3,368	4,131
0.75% Japanese yen notes, due 2012
Debt Outstanding [Line Items]
Long-term debt	1,020
0.84% Japanese yen notes, due 2013
Debt Outstanding [Line Items]
Long-term debt	¥ 156

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Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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Including the current and noncurrent portions, aggregate carrying value as of the balance sheet date of loans payable (with maturities initially due after one year or beyond the operating cycle if longer).

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