Weighted-Average Actuarial Assumptions (Detail)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Japanese Pension Plan
Weighted-average actuarial assumptions:
Discount rate - net periodic benefit cost	2.25%		2.50%		2.50%
Discount rate - benefit obligations	2.25%		2.25%		2.50%
Expected long-term return on plan assets	2.50%		2.50%		2.50%
U.S. Pension Plan
Weighted-average actuarial assumptions:
Discount rate - net periodic benefit cost	5.50%		5.75%		6.25%
Discount rate - benefit obligations	4.75%		5.50%		5.75%
Expected long-term return on plan assets	7.50%		7.50%		8.00%
Rate of compensation Increase	4.00%		4.00%		4.00%
Other Postretirement Benefit Plans, Defined Benefit
Weighted-average actuarial assumptions:
Discount rate - net periodic benefit cost	5.50%		5.75%		6.25%
Discount rate - benefit obligations	4.75%		5.50%		5.75%
Health care cost trend rates	7.30%	[1]	7.50%	[1]	6.70%	[1]

[1] In the years 2011, 2010 and 2009, the health care cost trend rates were expected to trend down to 4.2%, 3.9% and 4.5%, respectively, in 75 years