Financial Instruments (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 02, 2016	Jul. 04, 2015	Jul. 02, 2016	Jul. 04, 2015	Dec. 31, 2015
Derivative [Line Items]
Interest rate cap hedges recognized in other comprehensive income, net of tax	$ (148,000)	$ 0	$ (556,000)	$ 0
Other Current Assets
Derivative [Line Items]
Derivative asset	0		0		$ 1,000
Other Long Term Assets
Derivative [Line Items]
Derivative asset	156,000		156,000		962,000
Interest rate cap premiums
Derivative [Line Items]
Interest rate cap hedges recognized in other comprehensive income, net of tax	(100,000)
Derivative, Gain (Loss) on Derivative, Net			0
Cash Flow Hedging | Designated as Hedging Instrument | Interest rate cap premiums | Other Current Assets
Derivative [Line Items]
Derivative asset	0		0		1,000
Cash Flow Hedging | Designated as Hedging Instrument | Interest rate cap premiums | Other Long Term Assets
Derivative [Line Items]
Derivative asset	$ 156,000		$ 156,000		$ 962,000