Fair Value Measurements, Measured On Recurring Basis Significant Unobservable Inputs (Details) - Fair Value, Recurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($)		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Available-for-sale securities [Member] | Municipal and other tax-exempt securities [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period		$ 0	$ 4,802,000
Transfer to Level 3 from Level 2	[1]	0	0
Purchases		0	0
Redemptions and distributions		0	(5,095,000)
Proceeds from sales		0	0
Other comprehensive income (loss)		0	293,000
Balance, end of period		0	0
Available-for-sale securities [Member] | Municipal and other tax-exempt securities [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		0	0
Available-for-sale securities [Member] | Other debt securities [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period		472,000	472,000
Transfer to Level 3 from Level 2	[1]	0	0
Purchases		0	0
Redemptions and distributions		0	0
Proceeds from sales		0	0
Other comprehensive income (loss)		0	0
Balance, end of period		472,000	472,000
Available-for-sale securities [Member] | Other debt securities [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		0	0
Residential mortgage loans held for sale [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period		15,207,000	12,299,000
Transfer to Level 3 from Level 2	[1]	2,449,000	6,183,000
Purchases		0	0
Redemptions and distributions		0	0
Proceeds from sales		(9,972,000)	(2,706,000)
Other comprehensive income (loss)		0	0
Balance, end of period		8,313,000	15,207,000
Residential mortgage loans held for sale [Member] | Mortgage banking revenue [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Gain (loss) recognized in earnings		$ 629,000	$ (569,000)

[1] Recurring transfers to Level 3 from Level 2 consist of residential mortgage loans intended for sale to U.S. government agencies that fail to meet conforming standards.