Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	$ 1,187,676	$ 977,830
Unrealized Gains	(37,351)	(43,354)
Unrealized Losses	(5,402)	(440)
Securities available-for-sale	1,219,625	1,020,744
US Government Agencies Debt Securities [Member]
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	106,775	92,710
Unrealized Gains	(4,610)	(5,105)
Unrealized Losses	(35)	(1)
Securities available-for-sale	111,350	97,814
Mortgage Backed Securities - Residential
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	521,939	346,606
Unrealized Gains	(6,137)	(8,794)
Unrealized Losses	(4,338)	(279)
Securities available-for-sale	523,738	355,121
Mortgage Backed Securities - Commercial
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	15,700	17,931
Unrealized Gains	(408)	(559)
Unrealized Losses	0	0
Securities available-for-sale	16,108	18,490
Collateralized Mortgage Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	180,788	209,556
Unrealized Gains	(3,024)	(4,761)
Unrealized Losses	(613)	(157)
Securities available-for-sale	183,199	214,160
State and Municipal Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	331,748	285,837
Unrealized Gains	(19,470)	(20,294)
Unrealized Losses	(274)	0
Securities available-for-sale	350,944	306,131
Collateralized Debt Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	0	0
Unrealized Gains	(3,265)	(3,136)
Unrealized Losses	0	0
Securities available-for-sale	$ 3,265	$ 3,136