Securities - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Realized gains on available-for-sale debt securities	$ 0		$ 0
Realized losses on available-for-sale debt securities	62,900,000	$ 49,000	70,000,000	$ 49,000
Available-for-sale securities sold	$ 429,600,000		510,500,000
Available-for-sale securities sold, average yield	0.93%
Available-for-sale securities sold, average yield of reinvested securities	5.12%
Weight average life of securities purchased and sold	4 years 3 months 18 days
Proceeds from sales of available-for-sale debt securities	$ 366,700,000	24,600,000	440,488,000	24,621,000
Realized gains on called available-for-sale debt securities	0	0	0	0
Net losses on equity securities	36,700	$ 46,900	35,700	$ 130,600
Federal Home Loan Bank New York (FHLBNY)
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Holdings of FHLBNY, FHLBPITT and ACBB stock, amount of advances	19,900,000		19,900,000
Atlantic Central Bankers Bank (ACBB)
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Holdings of FHLBNY, FHLBPITT and ACBB stock, amount of advances	$ 95,000		$ 95,000