Securities - Additional Information (Details)	6 Months Ended
	Jun. 30, 2022 USD ($) item security	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Additional Information
The number of holdings of securities of any one issuer other than the U.S. Government and its sponsored entities | security	0
Holdings of securities as percentage of shareholders' equity, considered as threshold for disclosure purpose	10.00%
Number of securities held | item	430
Number of available for sale securities held | item	144
Number of held to maturity securities held | item	286
Number of securities with fair values below amortized cost | item	366
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	$ 300,510,000
Debt Securities, Held-to-Maturity, Continuous Unrealized Losses Position, Less than 12 Months, Fair Value	603,989,000		$ 408,856,000
Debt Securities, Held-to-Maturity, Continuous Unrealized Losses Position, 12 Months or Longer, Fair Value		$ 29,473,000	27,997,000
Total unrealized loss for securities carried less than 12 months	(71,518,000)
Total unrealized loss for securities carried for 12 months or more	(5,909,000,000)
Agency mortgage-backed securities
Additional Information
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	81,550,000
Debt Securities, Held-to-Maturity, Continuous Unrealized Losses Position, Less than 12 Months, Fair Value	580,869,000		408,856,000
Debt Securities, Held-to-Maturity, Continuous Unrealized Losses Position, 12 Months or Longer, Fair Value	29,473,000	$ 29,473,000	$ 27,997,000
U.S. Treasury
Additional Information
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	218,960,000
Municipals - Tax Exempt
Additional Information
Debt Securities, Held-to-Maturity, Continuous Unrealized Losses Position, Less than 12 Months, Fair Value	$ 23,120,000