Derivative Instruments And Hedging Activities (Narrative) (Details) $ in Millions	6 Months Ended
Jun. 30, 2018 USD ($)
General Discussion Of Derivative Instruments And Hedging Activities [Abstract]
Average remaining life of interest rate swap agreements	1 year 7 months 6 days
Estimated derivatives to be reclassified as interest income	$ 5.5

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=112277219&loc=d3e80748-113994

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