Investment Securities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Investment [Line Items]
Other than Temporary Impairment Losses, Investments	$ 0	$ 0	$ 0
Pledged Financial Instruments, Not Separately Reported, Securities	396,300,000	328,600,000
Pledged Financial Instruments, Not Separately Reported, Securities for Repurchase Agreements	327,900,000	348,600,000
Pledged Financial Instruments, Not Separately Reported, Securities for Federal Home Loan Bank	9,500,000	13,900,000
Schedule of Repurchase Agreement Counterparties with Whom Repurchase Agreements Exceed 10 Percent of Stockholders' Equity [Table Text Block]	$ 0
Percentage of amount greater than shareholder's equity	10.00%
Debt Securities, Available for Sale, Sold at Gain, Amortized Cost Amount	$ 0	196,400,000	29,100,000
Debt Securities, Available for Sale, Sold at Loss, Amortized Cost Amount		112,500,000	62,400,000
Debt Securities, Available-for-sale, Realized Gain		3,400,000	271,000
Debt Securities, Available-for-sale, Realized Loss		64,000	700,000
Debt Securities, Held-to-maturity, Transfer, Amount			373,900,000
Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, Net of Tax	0	0	19,095,000
Gain on equity securities, net	5,011,000	2,182,000	5,118,000
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	73,431,000	4,727,000
Debt Securities, Available-for-sale, Allowance for Credit Loss	0
Debt Securities, Available-for-sale, Unrealized Loss Position	840,832,000	91,120,000
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	9,514,000	728,000
Debt Securities, Available-for-sale	1,754,140,000	$ 1,059,341,000
Investments [Member]
Investment [Line Items]
Gain on equity securities, net	$ 552,000		$ 345,000