Acquisitions - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 29, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013	Dec. 31, 2013
Business Acquisition [Line Items]
Fair value of the consideration at the date of acquisition					$ 307,000,000
Net revenues	468,105,000	420,059,000	906,651,000	831,936,000
Income from continuing operations before taxes	58,836,000	49,483,000	102,639,000	84,851,000
Mayo Healthcare Pty Limited
Business Acquisition [Line Items]
Fair value of the consideration at the date of acquisition	28,500,000		28,500,000
Initial payment			29,000,000
Working capital adjustment related to acquisition			500,000
Transaction expenses			300,000
Net revenues	9,400,000		13,500,000
Income from continuing operations before taxes	$ 3,200,000		$ 3,800,000
Mayo Healthcare Pty Limited | Customer Lists
Business Acquisition [Line Items]
Useful life of intangible assets acquired, years			10 years