Purchase Price Allocation (Detail) (Walker, USD $) In Thousands, unless otherwise specified	May 08, 2012
Walker
Business Combination Allocation Of Purchase Price [Line Items]
Cash	$ 10,982
Current assets	93,409
Property, plant and equipment	32,541
Intangibles	162,800
Deferred income taxes	4,640
Goodwill	148,498
Total assets	452,870
Current liabilities	(74,722)
Deferred income taxes	(1,100)
Total liabilities	(75,822)
Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net	377,048
Business acquisition cost of acquired entity purchase price	$ 366,066