Financial Instruments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Derivative [Line Items]
Interest rate cap hedges recognized in other comprehensive income, net of tax	$ 305,000	$ 0	$ 0
Other Current Assets
Derivative [Line Items]
Derivative asset	0	1,000
Other Long Term Assets
Derivative [Line Items]
Derivative asset	553,000	962,000
Interest rate cap premiums
Derivative [Line Items]
Interest rate cap hedges recognized in other comprehensive income, net of tax	300,000
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	1,000
Cash Flow Hedging | Designated as Hedging Instrument | Interest rate cap premiums | Other Long Term Assets
Derivative [Line Items]
Derivative asset	$ 553,000	$ 962,000