Derivative Instruments (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Maximum \| Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Loss on Fair Value Hedge Ineffectiveness	$ 0.1	$ 0.1	$ 0.1

Amount of recognized loss from the hedging ineffectiveness of a fair value hedge.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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