Derivative Instruments (Impact Of Derivatives On Balance Sheet) (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Other assets
Derivative [Line Items]
Fair value of derivative assets	$ 11,336	$ 11,722
Other assets \| Interest rate contracts
Derivative [Line Items]
Fair value of derivative assets	10,034	10,786
Other assets \| Mortgage derivatives
Derivative [Line Items]
Fair value of derivative assets	1,302	936
Other assets \| Visa derivative
Derivative [Line Items]
Fair value of derivative assets	0	0
Other liabilities
Derivative [Line Items]
Fair value of derivative liabilities	25,494	17,097
Other liabilities \| Interest rate contracts
Derivative [Line Items]
Fair value of derivative liabilities	19,303	12,638
Other liabilities \| Mortgage derivatives
Derivative [Line Items]
Fair value of derivative liabilities	248	129
Other liabilities \| Visa derivative
Derivative [Line Items]
Fair value of derivative liabilities	$ 5,943	$ 4,330

Fair value, after offset of derivative asset, of financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, elected not to be and before offset against a right to receive collateral under a master netting arrangement. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=d3e41678-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226006-175313

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Name:	us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant