Investments - Carrying value and estimated fair value (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities
Amortized Cost	$ 1,231,730	$ 1,098,373
Gross Unrealized Gains	2,385	20,373
Gross Unrealized Losses	(72,359)	(9,538)
Available-for-sale debt securities	1,161,756	1,109,208
U.S. Government agencies
Schedule of Available-for-sale Securities
Amortized Cost	356	373
Gross Unrealized Gains	0	6
Gross Unrealized Losses	(12)	0
Available-for-sale debt securities	344	379
U.S. Treasury securities
Schedule of Available-for-sale Securities
Amortized Cost	9,988	9,988
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(730)	(63)
Available-for-sale debt securities	9,258	9,925
Obligations of states and political subdivisions
Schedule of Available-for-sale Securities
Amortized Cost	438,990	512,952
Gross Unrealized Gains	1,543	16,703
Gross Unrealized Losses	(31,404)	(3,188)
Available-for-sale debt securities	409,129	526,467
U.S. Government sponsored entities and agencies collateralized by residential mortgage obligations
Schedule of Available-for-sale Securities
Amortized Cost	226,466	213,471
Gross Unrealized Gains	329	2,245
Gross Unrealized Losses	(5,491)	(1,277)
Available-for-sale debt securities	221,304	214,439
Private label mortgage and asset backed securities
Schedule of Available-for-sale Securities
Amortized Cost	508,430	317,089
Gross Unrealized Gains	308	824
Gross Unrealized Losses	(32,925)	(4,693)
Available-for-sale debt securities	475,813	313,220
Corporate debt securities
Schedule of Available-for-sale Securities
Amortized Cost	47,500	44,500
Gross Unrealized Gains	205	595
Gross Unrealized Losses	(1,797)	(317)
Available-for-sale debt securities	$ 45,908	$ 44,778

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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