Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	$ 867,416	$ 907,575
Unrealized Gains	(40,251)	(20,976)
Unrealized Losses	(234)	(1,834)
Securities available-for-sale	907,433	926,717
US Government Agencies Debt Securities [Member]
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	92,391	102,490
Unrealized Gains	(4,344)	(1,293)
Unrealized Losses	(3)	(150)
Securities available-for-sale	96,732	103,633
Mortgage Backed Securities - Residential
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	228,141	240,753
Unrealized Gains	(9,007)	(2,979)
Unrealized Losses	0	(350)
Securities available-for-sale	237,148	243,382
Mortgage Backed Securities - Commercial
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	18,157
Unrealized Gains	(667)
Unrealized Losses	0
Securities available-for-sale	18,824	22,104
Collateralized Mortgage Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	243,703	280,797
Unrealized Gains	(6,306)	(1,735)
Unrealized Losses	(124)	(1,221)
Securities available-for-sale	249,885	281,311
State and Municipal Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	270,171	253,277
Unrealized Gains	(16,684)	(11,265)
Unrealized Losses	(107)	(108)
Securities available-for-sale	286,748	264,434
Collateralized Debt Obligations
Amortized cost and fair value of investments classified as available for sale
Amortized Cost	0	0
Unrealized Gains	(2,945)	(3,619)
Unrealized Losses	0	0
Securities available-for-sale	$ 2,945	$ 3,619