Right-of-Use Assets and Operating Lease Liabilities (Lease Information) (Details) $ in Thousands	Dec. 31, 2020 USD ($) lease
Lessee, Lease, Description [Line Items]
Number of ground leases | lease	3
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssets
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilities
Ground Leases
Lessee, Lease, Description [Line Items]
Operating lease – ROU assets	$ 4,211
Operating lease – lease liabilities	$ (5,859)
Weighted average remaining lease term	13 years 4 months 24 days
Weighted average discount rate	4.10%
Operating lease - accrued lease payments	$ 1,648
Headquarters Office Lease
Lessee, Lease, Description [Line Items]
Operating lease – ROU assets	2,471
Operating lease – lease liabilities	$ (3,021)
Weighted average remaining lease term	4 years 3 months 18 days
Weighted average discount rate	3.50%
Operating lease - accrued lease payments	$ 550