Securities - Securities gross unrealized losses and fair value, aggregated by investment category and length of time (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Less Than 12 Months
Fair Value	$ 920,466	$ 628,487
Unrealized Losses	(111,133)	(8,121)
More Than 12 Months
Fair Value	361,835	74,187
Unrealized Losses	(88,119)	(2,061)
Total
Fair Value	1,282,301	702,674
Unrealized Losses	(199,252)	(10,182)
U.S. Government agencies
Less Than 12 Months
Fair Value	83,013	48,939
Unrealized Losses	(6,952)	(739)
More Than 12 Months
Fair Value	22,164	146
Unrealized Losses	(4,718)	(2)
Total
Fair Value	105,177	49,085
Unrealized Losses	(11,670)	(741)
Mortgage Backed Securities - residential
Less Than 12 Months
Fair Value	364,927	436,726
Unrealized Losses	(48,470)	(5,281)
More Than 12 Months
Fair Value	252,690	60,807
Unrealized Losses	(57,668)	(1,598)
Total
Fair Value	617,617	497,533
Unrealized Losses	(106,138)	(6,879)
Mortgage Backed Securities - commercial
Less Than 12 Months
Fair Value	11,309
Unrealized Losses	(454)
Total
Fair Value	11,309
Unrealized Losses	(454)
Collateralized Mortgage Obligations
Less Than 12 Months
Fair Value	153,183	73,530
Unrealized Losses	(14,893)	(1,327)
More Than 12 Months
Fair Value	43,137	12,505
Unrealized Losses	(8,984)	(441)
Total
Fair Value	196,320	86,035
Unrealized Losses	(23,877)	(1,768)
State and municipal obligations
Less Than 12 Months
Fair Value	280,127	54,040
Unrealized Losses	(35,118)	(578)
More Than 12 Months
Fair Value	38,129
Unrealized Losses	(15,207)
Total
Fair Value	318,256	54,040
Unrealized Losses	(50,325)	(578)
Municipal taxable
Less Than 12 Months
Fair Value	25,851	15,048
Unrealized Losses	(5,218)	(195)
More Than 12 Months
Fair Value	5,715	729
Unrealized Losses	(1,542)	(20)
Total
Fair Value	31,566	15,777
Unrealized Losses	(6,760)	(215)
U.S. Treasury
Less Than 12 Months
Fair Value	2,056	204
Unrealized Losses	(28)	(1)
Total
Fair Value	2,056	204
Unrealized Losses	$ (28)	$ (1)

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