Derivatives (Fair Value of the Company's Other Derivatives) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Not Designated as Hedging Instrument | Other long term liabilities | Interest rate contracts
Derivative [Line Items]
Derivative liabilities	$ 193	$ (1,244)	$ (1,929)
Not Designated as Hedging Instrument | Accrued expenses and other current liabilities | Foreign currency contract
Derivative [Line Items]
Derivative liabilities	(737)	426	1,605
Designated as Hedging Instrument | Other assets | Interest rate contracts
Derivative [Line Items]
Derivative assets	$ 227	$ 0	$ 0