Parent Corporation Only Financial Statements (Details) - Condensed Statements of Condition - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
ASSETS
Cash and cash equivalents	$ 63,637	$ 65,717
Securities available-for-sale	487,955	404,701
Other assets	88,458	59,465
Total assets	7,547,339	6,174,032
LIABILITIES AND STOCKHOLDERS' EQUITY
Other liabilities	26,177	29,673
Subordinated debentures	202,648	128,885
Stockholders' equity	915,310	731,190
Total liabilities and stockholders' equity	7,547,339	6,174,032
Parent Company [Member]
ASSETS
Cash and cash equivalents	34,388	21,392
Investment in subsidiaries	1,001,998	810,705
Receivable due from subsidiaries	32,250	32,250
Securities available-for-sale	155	155
Other assets	51,288	1,282
Total assets	1,120,079	865,784
LIABILITIES AND STOCKHOLDERS' EQUITY
Other liabilities	2,121	5,709
Subordinated debentures	202,648	128,855
Stockholders' equity	915,310	731,190
Total liabilities and stockholders' equity	$ 1,120,079	$ 865,784