Allowance for Credit Losses and Credit Quality of Loans, Summary (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2022	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Allowance for Credit Losses [Abstract]
Allowance for credit losses	$ 100,400	$ 100,800	$ 100,250	$ 93,600	$ 90,000	$ 92,000
Percentage of allowance of credit losses	1.20%	1.24%
Recorded total loans	$ 8,358,124	$ 8,150,147
Loans purchased with credit deterioration	0	0
Allowance for credit losses on loans purchased	17	3,200
ASU 2022-02 [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	100,400	100,152
Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASU 2022-02 [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses		(600)
Accrued Interest Receivable [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	0	0
AIR on loans	$ 28,000	$ 25,000
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Other Assets	Other Assets
PPP [Member] | Maximum [Member]
Allowance for Credit Losses [Abstract]
Recorded total loans			1,000
Residential [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	$ 15,554		15,390	16,302	17,852	18,806
Recorded total loans	2,129,758	$ 2,114,495
Amount of loans purchased	$ 2,400	$ 11,500
Premium on loans purchased	7.01%	1.53%
Residential [Member] | ASU 2022-02 [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	$ 15,554	$ 14,539
Consumer Loans [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	47,883		$ 48,820	$ 44,940	$ 43,591	$ 44,253
Recorded total loans	2,159,364	2,099,087
Amount of loans purchased		50,100
Consumer Loans [Member] | ASU 2022-02 [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	$ 47,883	$ 50,951