Revenue from Contract with Customers (Disaggregation by Timing of Revenue Recognition) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from contracts with customers		$ 45,152	$ 45,930	$ 47,066
Investment Advisory, Management and Administrative Service [Member]
Revenues from contracts with customers	[1]	35,454	36,848	38,341
Investment Advisory, Management and Administrative Service [Member] | Transferred over Time [Member]
Revenues from contracts with customers		35,454	36,848	38,341
Card Interchange Fees [Member]
Revenues from contracts with customers	[1]	4,287	4,214	3,768
Card Interchange Fees [Member] | Transferred at Point in Time [Member]
Revenues from contracts with customers		4,287	4,214	3,768
Deposit Account [Member]
Revenues from contracts with customers	[1]	2,742	3,684	3,628
Deposit Account [Member] | Transferred at Point in Time [Member]
Revenues from contracts with customers		2,103	2,850	2,802
Deposit Account [Member] | Transferred over Time [Member]
Revenues from contracts with customers		639	834	826
Other Noninterest Income [Member]
Revenues from contracts with customers	[1]	2,669	1,184	1,329
Other Noninterest Income [Member] | Transferred at Point in Time [Member]
Revenues from contracts with customers		2,494	989	958
Other Noninterest Income [Member] | Transferred over Time [Member]
Revenues from contracts with customers		$ 175	$ 195	$ 371

[1] Revenue from contracts with customers in scope of ASC 606.