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				6 Months Ended
	Jun. 30, 2019		Jun. 30, 2018		Jun. 30, 2019		Jun. 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	$ 0		$ 1,891		$ 0		$ 4,802
Transfer to Level 3 from Level 2	0	[1]	0	[2]	0	[1]	0	[3]
Purchases	0		0		0		0
Proceeds from sales	0		0		0		0
Redemptions and distributions	0		0		0		(3,045)
Other comprehensive income (loss)	0		139		0		273
Balance, end of period	0		2,030		0		2,030
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		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		472		472		472
Transfer to Level 3 from Level 2	0	[1]	0	[2]	0	[1]	0	[3]
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		(1)
Balance, end of period	472		471		472		471
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	15,776		13,871		15,207		12,299
Transfer to Level 3 from Level 2	907	[1]	687	[2]	1,889	[1]	2,843	[3]
Purchases	0		0		0		0
Proceeds from sales	(998)		(488)		(1,379)		(812)
Redemptions and distributions	0		0		0		0
Other comprehensive income (loss)	0		0		0		0
Balance, end of period	16,073		14,243		16,073		14,243
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	$ 388		$ 173		$ 356		$ (87)

[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.