Fair Value Measurements, Measured On Recurring Basis Significant Unobservable Inputs (Details) - Fair Value, Recurring [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2019		Sep. 30, 2018		Sep. 30, 2019		Sep. 30, 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			$ 2,030				$ 4,802
Transfer to Level 3 from Level 2			0	[1]			0	[2]
Purchases			0				0
Proceeds from sales			0				0
Redemptions and distributions			(2,050)				(5,095)
Other comprehensive income (loss)			20				293
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		471		$ 472		472
Transfer to Level 3 from Level 2	0	[3]	0	[1]	0	[3]	0	[2]
Purchases	0		0		0		0
Proceeds from sales	0		0		0		0
Redemptions and distributions	0		0		0		0
Other comprehensive income (loss)	0		1		0		0
Balance, end of period	472		472		472		472
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		0		0
Residential mortgage loans held for sale [Member]
Fair Value Assets Measured on Recurring Basis Unobservable Reconciliation [Roll Forward]
Balance, beginning of period	16,073		14,243		15,207		12,299
Transfer to Level 3 from Level 2	261	[3]	2,862	[1]	2,150	[3]	5,603	[2]
Purchases	0		0		0		0
Proceeds from sales	(3,152)		(143)		(4,531)		(853)
Redemptions and distributions	0		0		0		0
Other comprehensive income (loss)	0		0		0		0
Balance, end of period	13,568		16,838		13,568		16,838
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	$ 386		$ (124)		$ 742		$ (211)

[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.

[2] 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.

[3] 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.