Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Non-interest income
Returned item and overdraft fees										$ 6,854		$ 6,574
Other service charges on deposits										5,888		5,865
Debit card interchange income										6,584		5,878
Loss on limited partnerships										(2,079)		(2,561)
Dividends on equity investments										789	[1]	961	[1]	$ 761
Unrealized gains recognized on equity investments	[1]									232		1,183
Net gains on sale of securities										(198)	[1]	2	[1]	500
Other	[1]									5,407		3,662
Total non-interest income		$ 5,847	$ 5,869	$ 5,855	$ 5,906	$ 5,279	$ 5,723	$ 5,429	$ 5,133	23,477		21,564		21,779
Non-interest expense
Salaries and employee benefits										35,978	[1]	36,133	[1]	31,506
Occupancy expense										9,845	[1]	10,295	[1]	9,590
Gain on sale of foreclosed assets										(107)		(1,423)		(56)
Other	[1]									24,862		25,019
Total non-interest expense		$ 17,982	$ 17,088	$ 17,656	$ 17,852	$ 17,036	$ 17,807	$ 17,294	$ 17,887	$ 70,578		$ 70,024		$ 65,441

[1] Not within the scope of ASC 606. Revenue streams are not related to contracts with customers and are accounted for on an accrual basis under other provisions of GAAP.