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Securities - Narrative (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Allowance for Credit Loss	$ 0		$ 0		$ 0
Transferred Securities, Unrealized Loss, Before Tax	91,500,000		91,500,000		1,500,000
Securities transferred, Unrealized Loss, Net of Tax	72,300,000		72,300,000		1,200,000
Fair value of securities transferred from AFS to HTM			998,500,000		0
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Net gain (loss) on sale of securities AFS	(2,177,000)	$ 15,000	(3,720,000)	$ 2,018,000
Gross realized gains on AFS securities			290,000	2,100,000
Gross realized losses on AFS securities			4,000,000	52,000
Equity investments	11,282,000		11,282,000		11,841,000
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]
Sale of HTM portfolio			0	0
Interest receivable	41,539,000		41,539,000		39,145,000
Debt Securities, Held-to-maturity, Nonaccrual	0		0		0
FHLB stock with other-than-temporary impairment	0		0
Other-than-temporarily impaired equity investments	$ 0		$ 0
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions	644		644
State and political subdivisions
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, Credit Loss Expense (Reversal)	$ 0	0	$ 0	0
Corporate bonds and other
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]
Debt Securities, Held-to-Maturity, Excluding Accrued Interest, Credit Loss Expense (Reversal)	0	$ 0	0	$ 0
Asset Pledged as Collateral
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]
Debt Securities	1,410,000,000		1,410,000,000		1,610,000,000
Financial Asset, Past Due
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]
Securities held to maturity (estimated fair value of $138,879)	0		0		0
Available-for-sale Securities
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]
Interest receivable	16,100,000		16,100,000		25,600,000
Held-to-maturity Securities
Debt Securities, Held-to-maturity, Sale or Transfer of Investment [Abstract]
Interest receivable	$ 10,900,000		$ 10,900,000		$ 244,000

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