Derivative Instruments (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Payments for (proceeds from) hedge, investing activities	$ 70,897	$ 52,719

The cash outflow or inflow for a financial contract that meets the hedge criteria as either a cash flow hedge, fair value hedge, or hedge of a net investment in a foreign operation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 27
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3581-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3098-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3095-108585

Name:	us-gaap_PaymentsForProceedsFromHedgeInvestingActivities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration