Derivatives and Hedging (Narrative) (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Accumulated unrealized gain (loss) on foreign currency contracts , net of tax		$ (100,000)
Maximum [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Accumulated unrealized gain (loss) on foreign currency contracts , net of tax	$ 100,000
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	$ 1,100,000	$ 4,500,000

Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=114867106&loc=d3e637-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669646-108580

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=114867106&loc=d3e681-108580

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