Securities, Available for Sale, Gross Unrealized Losses and Fair Values (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($) Security	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized cost	$ 1,461,677		$ 1,404,858
Unrealized Gains	2,651		16,594
Unrealized Losses	64,191		8,622
Fair Value	1,400,137		1,412,830
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	1,029,245		607,923
Less Than Twelve Months, Unrealized Losses	53,534		8,077
Twelve Months or More, Fair Value	122,856		33,530
Twelve Months or More, Unrealized Losses	10,657		545
Total, Fair Value	1,152,101		641,453
Total, Unrealized Losses	64,191		8,622
Available-for-sale, allowance for credit losses	0
Accrued interest receivable	6,100		6,000
Credit related charges recognized in earnings	0	$ 0
U.S. Agency [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized cost	45,896		34,634
Unrealized Gains	21		152
Unrealized Losses	2,329		112
Fair Value	43,588		34,674
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	38,843		11,986
Less Than Twelve Months, Unrealized Losses	2,327		109
Twelve Months or More, Fair Value	1,006		1,286
Twelve Months or More, Unrealized Losses	2		3
Total, Fair Value	39,849		13,272
Total, Unrealized Losses	$ 2,329		112
Number of securities with market fair value less than amortized cost | Security	41
U.S. Agency Residential Mortgage-Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized cost	$ 292,590		309,907
Unrealized Gains	574		1,952
Unrealized Losses	16,161		3,874
Fair Value	277,003		307,985
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	125,161		171,398
Less Than Twelve Months, Unrealized Losses	8,226		3,555
Twelve Months or More, Fair Value	84,351		19,024
Twelve Months or More, Unrealized Losses	7,935		319
Total, Fair Value	209,512		190,422
Total, Unrealized Losses	$ 16,161		3,874
Number of securities with market fair value less than amortized cost | Security	167
U.S. Agency Commercial Mortgage-Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized cost	$ 22,663		23,066
Unrealized Gains	0		84
Unrealized Losses	1,072		224
Fair Value	21,591		22,926
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	20,971		19,900
Less Than Twelve Months, Unrealized Losses	1,028		224
Twelve Months or More, Fair Value	598		0
Twelve Months or More, Unrealized Losses	44		0
Total, Fair Value	21,569		19,900
Total, Unrealized Losses	$ 1,072		224
Number of securities with market fair value less than amortized cost | Security	29
Private Label Mortgage-Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized cost	$ 115,928		102,480
Unrealized Gains	277		807
Unrealized Losses	4,122		672
Fair Value	112,083		102,615
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	102,999		64,408
Less Than Twelve Months, Unrealized Losses	4,058		640
Twelve Months or More, Fair Value	2,055		2,180
Twelve Months or More, Unrealized Losses	64		32
Total, Fair Value	105,054		66,588
Total, Unrealized Losses	$ 4,122		672
Number of securities with market fair value less than amortized cost | Security	90
Other Asset Backed [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized cost	$ 281,822		215,235
Unrealized Gains	414		1,204
Unrealized Losses	3,080		269
Fair Value	279,156		216,170
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	212,965		86,581
Less Than Twelve Months, Unrealized Losses	3,060		248
Twelve Months or More, Fair Value	979		978
Twelve Months or More, Unrealized Losses	20		21
Total, Fair Value	213,944		87,559
Total, Unrealized Losses	$ 3,080		269
Number of securities with market fair value less than amortized cost | Security	121
Obligations of States and Political Subdivisions [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized cost	$ 550,439		568,355
Unrealized Gains	842		9,942
Unrealized Losses	31,203		2,221
Fair Value	520,078		576,076
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	417,842		178,484
Less Than Twelve Months, Unrealized Losses	28,911		2,151
Twelve Months or More, Fair Value	30,159		7,093
Twelve Months or More, Unrealized Losses	2,292		70
Total, Fair Value	448,001		185,577
Total, Unrealized Losses	$ 31,203		2,221
Number of securities with market fair value less than amortized cost | Security	795
Corporate [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized cost	$ 149,863		148,707
Unrealized Gains	521		2,446
Unrealized Losses	6,133		1,194
Fair Value	144,251		149,959
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	110,464		75,166
Less Than Twelve Months, Unrealized Losses	5,924		1,150
Twelve Months or More, Fair Value	1,823		1,050
Twelve Months or More, Unrealized Losses	209		44
Total, Fair Value	112,287		76,216
Total, Unrealized Losses	$ 6,133		1,194
Number of securities with market fair value less than amortized cost | Security	90
Trust Preferred [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized cost	$ 1,976		1,975
Unrealized Gains	0		0
Unrealized Losses	91		56
Fair Value	1,885		1,919
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less Than Twelve Months, Fair Value	0		0
Less Than Twelve Months, Unrealized Losses	0		0
Twelve Months or More, Fair Value	1,885		1,919
Twelve Months or More, Unrealized Losses	91		56
Total, Fair Value	1,885		1,919
Total, Unrealized Losses	$ 91		56
Number of securities with market fair value less than amortized cost | Security	2
Number of issues rated as investment grade | Security	1
Number of securities not rated | Security	1
Non-rated securities, amortized cost	$ 1,000
Fair value of non-rated trust preferred securities	940
Foreign Government [Member]
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Amortized cost	500		499
Unrealized Gains	2		7
Unrealized Losses	0		0
Fair Value	$ 502		$ 506