Goodwill and Intangible Assets (Schedule of Components of Intangible Assets) (Details) - Advisory Contracts [Member] - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 20,803	$ 20,803
Accumulated amortization	14,498	13,585
Net amount	$ 6,305	$ 7,218