Fair Value Of Assets And Liabilities (Summary Of Changes In Level 3 Assets And Liabilities Measured At Fair Value) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	$ (5,645)	$ (5,950)	$ (5,645)	$ (6,245)
Net income	(4,079)	(49)	(4,375)	(50)
Purchases	0	0	0	0
Sales	0		0
Settlements	299	299	595	595
Net transfers into/(out of) Level 3	0	0	0	0
Ending balance	(9,425)	(5,700)	(9,425)	(5,700)
Net unrealized gains/(losses) included in net income	(4,079)	(49)	(4,375)	(50)
Trading securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,926	2,335	2,151	2,573
Net income	124	271	140	288
Purchases	0	0	0	0
Sales	0		0
Settlements	(326)	(142)	(567)	(397)
Net transfers into/(out of) Level 3	0	0	0	0
Ending balance	1,724	2,464	1,724	2,464
Net unrealized gains/(losses) included in net income	87	229	63	202
Interest- only strips- AFS
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	2,733	0	1,270	0
Net income	(296)	267	1,296	267
Purchases	0	1,413	0	1,413
Sales	0		0
Settlements	0	(3,291)	(9,193)	(3,291)
Net transfers into/(out of) Level 3	3,350	2,774	12,414	2,774
Ending balance	5,787	1,163	5,787	1,163
Net unrealized gains/(losses) included in net income	(128)	(53)	(109)	(53)
Loans held- for-sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	18,334	21,221	18,926	21,924
Net income	540	410	709	1,332
Purchases	34	43	62	75
Sales	0		0
Settlements	(2,134)	(827)	(2,923)	(2,401)
Net transfers into/(out of) Level 3	(56)	(260)	(56)	(343)
Ending balance	16,718	20,587	16,718	20,587
Net unrealized gains/(losses) included in net income	$ 542	$ 410	$ 709	$ 1,332