Significant Accounting Policies (Schedule Of Depreciation And Useful Lives Of Real Estate And Intangible Assets) (Details)	3 Months Ended
Mar. 31, 2019
Building [Member]
Finite-Lived Intangible Assets [Line Items]
Standard depreciable life	40 years
Building Improvements [Member] \| Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Standard depreciable life	5 years
Building Improvements [Member] \| Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Standard depreciable life	40 years

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration