Loans And Allowance For Credit Losses (Summary Of Net Financial Impact On Interest Income Due To Interest Rate Modifications Below Market For Accruing TDR Loans) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 6,676	$ 604	$ 6,863	$ 2,475	$ 139,400	$ 93,400
Loans and Leases Receivable, Gross, Consumer, Home Equity	2,581,068		2,581,068				$ 2,416,357
Net financial impact on interest income	402	490	1,254	1,624
Commercial [Member]
Financing Receivable, Modifications [Line Items]
Net financial impact on interest income	138	113	388	419
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Net financial impact on interest income	(1)	(26)	(3)	(88)
Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Loans and Leases Receivable, Gross, Consumer, Home Equity	2,581,068		2,581,068				$ 2,416,357
Net financial impact on interest income	198	267	645	822
Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	3,360	0	3,360	943
Net financial impact on interest income	(49)	(46)	(148)	(230)
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	6,631	9	6,700	1,047
Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	45	0	45	833
Net financial impact on interest income	(65)	(84)	(218)	(295)
One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	595	118	595
Net financial impact on interest income	(194)	(260)	(630)	(800)
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0
Net financial impact on interest income	(4)	(7)	(14)	(21)
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	45	0	45	833
Net financial impact on interest income	66	110	221	383
Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0
Net financial impact on interest income	0	0	(1)	(1)
Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	595	118	595
Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	3,285	604	3,472	2,475
Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	943
Nonaccruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	3,240	9	3,309	1,047
Nonaccruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	45	0	45	833
Nonaccruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	595	118	595
Nonaccruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0
Nonaccruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	45	0	45	833
Nonaccruing [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0
Nonaccruing [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	595	118	595
Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	3,391	0	3,391	0
Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	3,360	0	3,360	0
Accruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	3,391	0	3,391	0
Accruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0
Accruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0
Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0
Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0
Accruing [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0	0	0
Accruing [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0	$ 0	$ 0	$ 0