Parent Corporation Only Financial Statements (Details) - Condensed Statements of Condition - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
ASSETS
Cash and cash equivalents	$ 65,717	$ 39,161
Securities available-for-sale	404,701	412,034
Equity securities	11,185	11,460
Other assets	59,465	30,216
Total assets	6,174,032	5,462,092
LIABILITIES AND STOCKHOLDERS' EQUITY
Other liabilities	29,673	27,516
Subordinated debentures	128,885	128,556
Stockholders' equity	731,190	613,927
Total liabilities and stockholders' equity	6,174,032	5,462,092
Parent Company [Member]
ASSETS
Cash and cash equivalents	21,392	22,071
Investment in subsidiaries	810,705	692,516
Receivable due from subsidiaries	32,250	32,250
Securities available-for-sale	155	176
Equity securities		607
Other assets	1,282	1,282
Total assets	865,784	748,902
LIABILITIES AND STOCKHOLDERS' EQUITY
Other liabilities	5,709	6,419
Subordinated debentures	128,855	128,556
Stockholders' equity	731,190	613,927
Total liabilities and stockholders' equity	$ 865,784	$ 748,902