Acquisitions - Willcare, Ingenios, Black Stone, LTS and Bayonne- (Details)					3 Months Ended
	Jan. 05, 2016 USD ($)	Aug. 29, 2015 USD ($)	Jul. 22, 2015 USD ($) item	Mar. 01, 2015 USD ($)	Apr. 01, 2016 USD ($)	Apr. 03, 2015 USD ($)	Apr. 01, 2015 USD ($)	Jan. 01, 2016 USD ($)	Dec. 31, 2014 USD ($)
Acquisitions
Cash paid					$ 24,229,000	$ 3,000,000
Approximate fair value estimates of the assets acquired and liabilities assumed
Goodwill					315,360,000			$ 277,061,000	$ 192,523,000
Deal and transition costs incurred							$ 406,000
Ingenios
Acquisitions
Purchase price			$ 11,400,000
Interest acquired (as a percent)			100.00%
Cash consideration			$ 2,000,000
Number of States | item			7
LTS
Acquisitions
Purchase price	$ 37,000,000
Bayonne
Acquisitions
Purchase price	$ 4,000,000
WillCare
Acquisitions
Purchase price		$ 50.800
Approximate fair value estimates of the assets acquired and liabilities assumed
Accounts receivable				$ 14,412,000
Property, plant & equipment				5,375,000
Other assets				2,033,000
Goodwill				122,675,000
Other intangibles				12,270,000
Assets acquired				156,765,000
Liabilities assumed				(9,301,000)
Net assets acquired				147,464,000
WillCare | Ingenios
Approximate fair value estimates of the assets acquired and liabilities assumed
Deal and transition costs incurred					$ 2,300,000
Ohio | WillCare
Acquisitions
Cash paid				$ 3,000