Summary of Significant Accounting Policies (Schedule of Estimated Useful Lives of Assets by Class) (Details) |
12 Months Ended |
|---|---|
Dec. 31, 2018 | |
| Building and improvements [Member] | Minimum [Member] | |
| Property, Plant and Equipment [Line Items] | |
| Estimated useful life | 15 years |
| Building and improvements [Member] | Maximum [Member] | |
| Property, Plant and Equipment [Line Items] | |
| Estimated useful life | 40 years |
| Furniture, fixtures, and equipment [Member] | Minimum [Member] | |
| Property, Plant and Equipment [Line Items] | |
| Estimated useful life | 3 years |
| Furniture, fixtures, and equipment [Member] | Maximum [Member] | |
| Property, Plant and Equipment [Line Items] | |
| Estimated useful life | 10 years |