Actuarial Assumptions used to Compute net Periodic Pension Cost for U.K. Plan and Japan Plan (Detail)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
UNITED KINGDOM
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average discount rate	4.90%	5.30%	5.80%
Weighted-average long-term rate of return on plan assets	5.00%	5.90%	6.50%
JAPAN
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average discount rate	1.20%	1.30%	1.30%
Weighted-average rate of compensation increase	3.00%	3.00%	3.00%
Weighted-average long-term rate of return on plan assets			0.10%