Derivative Instruments - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Payments for (proceeds from) hedge, investing activities	$ 0	$ 8,055

The cash 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/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 27
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3581-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

Name:	us-gaap_ProceedsFromHedgeInvestingActivities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration