Derivative Instruments And Hedging Activities - Unrealized Gain Recognized In OCI (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain Recognized in OCI (Effective Portion)	$ 2,153	$ 909
Foreign Exchange Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain Recognized in OCI (Effective Portion)	1,588	671
Interest Rate Swaps
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain Recognized in OCI (Effective Portion)	$ 565	$ 238

Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6441202&loc=d3e80720-113993

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669646-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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