Revenue from Contracts with Customers (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net interest income	$ 33,878	$ 33,449	$ 33,111	$ 31,852	$ 30,889	$ 30,059	$ 29,904	$ 28,679	$ 132,290	$ 119,531	$ 110,478
Asset-based wealth management revenues									37,343	38,125	36,139
Transaction-based wealth management revenues									998	1,221	1,430
Total wealth management revenues									38,341	39,346	37,569
Mortgage banking revenues									10,381	11,392	13,183
Service charges on deposit accounts									3,628	3,672	3,702
Card interchange fees									3,768	3,502	3,385
Income from bank-owned life insurance									2,196	2,161	2,659
Loan related derivative income									2,461	3,214	3,243
Other income									1,339	1,522	1,388
Total noninterest income	$ 15,163	$ 15,215	$ 15,993	$ 15,743	$ 16,210	$ 17,283	$ 16,806	$ 14,510	62,114	64,809	65,129
Total revenues									194,404	184,340	175,607
Revenue from Contract with Customer [Member]
Net interest income									0	0	0
Asset-based wealth management revenues									37,343	38,125	36,139
Transaction-based wealth management revenues									998	1,221	1,430
Total wealth management revenues									38,341	39,346	37,569
Mortgage banking revenues									0	0	0
Service charges on deposit accounts									3,628	3,672	3,702
Card interchange fees									3,768	3,502	3,385
Income from bank-owned life insurance									0	0	0
Loan related derivative income									0	0	0
Other income									1,329	1,469	1,388
Total noninterest income									47,066	47,989	46,044
Total revenues									$ 47,066	$ 47,989	$ 46,044