Goodwill and Other Intangibles (Schedule of Components of Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Advisory Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 20,803	$ 20,803
Accumulated amortization	11,663	10,648
Net amount	9,140	10,155
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	369	369
Accumulated amortization	369	349
Net amount	$ 0	$ 20