Derivatives and Hedging (Narrative) (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Accumulated unrealized gain (loss) on foreign currency contracts , net of tax	$ (78,000)	$ 21,000
Foreign Exchange Forward Contracts [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedges [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Notional value of derivative contracts	$ 3,900,000	$ 2,400,000