Acquisitions - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012 Year	Jul. 28, 2011
Business Acquisition [Line Items]
Business acquisition, cash paid		$ 10.6
Fair value of contingent consideration	1.1	0.9
Potential cash payment to shareholders	12.0
Contingent consideration expiration year	2015
Period for performance evaluation, years	4
Business acquisition, effective date	Jul. 28, 2011
Accrued Expenses and Other Current Liabilities
Business Acquisition [Line Items]
Fair value of contingent consideration	0.1
Other Noncurrent Liabilities
Business Acquisition [Line Items]
Fair value of contingent consideration	$ 1.1