Recovery of Purchase Price from Previous Acquisition - Additional Information (Detail)	1 Months Ended					9 Months Ended
	Mar. 31, 2012 USD ($)	Feb. 29, 2012 USD ($)	Feb. 29, 2012 GBP (£)	Nov. 30, 2011 USD ($)	Nov. 30, 2011 GBP (£)	Sep. 29, 2012 USD ($)
Business Combination, Separately Recognized Transactions [Line Items]
Proceeds from legal settlement		$ 50,000,000	£ 32,200,000	$ 8,800,000	£ 5,500,000
Pension plan, company contribution		58,000,000	37,700,000
Recovery of purchase price	68,300,000					68,314,000
Expenses incurred in prior periods	5,200,000
Recovery of purchase price, net amount	$ 63,100,000
Settlement agreement date	2012-01-06