Investment Securities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Investment [Line Items]
Other than Temporary Impairment Losses, Investments	$ 0	$ 0	$ 0
Pledged Financial Instruments, Not Separately Reported, Securities	329,000,000	370,000,000
Pledged Financial Instruments, Not Separately Reported, Securities for Repurchase Agreements	349,000,000	197,000,000
Pledged Financial Instruments, Not Separately Reported, Securities for Federal Home Loan Bank	14,000,000	18,000,000
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	$ 196,400,000	29,100,000	2,000,000.0
Debt Securities, Available for Sale, Sold at Loss, Amortized Cost Amount	112,500,000	62,400,000	245,000,000.0
Debt Securities, Available-for-sale, Realized Gain	3,400,000	271,000	60,000
Debt Securities, Available-for-sale, Realized Loss	64,000	$ 692,000	2,600,000
Debt Securities, Held-to-maturity, Sold, Amount			7,400,000
Debt Securities, Held-to-maturity, Sold, Realized Gain (Loss)			300,000
percent of held to securities sold paid down		96.30%
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	19,095,000	0
Gain on equity securities, net	2,182,000	$ 5,118,000	4,616,000
Investments [Member]
Investment [Line Items]
Gain on equity securities, net	$ (239,000)		(287,000)
Equity securities
Investment [Line Items]
Gain on equity securities, net			$ 3,500,000