Goodwill And Other Intangible Assets (Goodwill Assets by Business Segment) (Detail) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Goodwill [Roll Forward]
Beginning balance	$ 405,634,000us-gaap_Goodwill	$ 373,725,000us-gaap_Goodwill
Goodwill Acquired	16,718,000us-gaap_GoodwillAcquiredDuringPeriod
Impairment Loss	0us-gaap_GoodwillImpairmentLoss
Goodwill Adjustments	(2,155,000)
Ending balance	420,197,000us-gaap_Goodwill	373,725,000us-gaap_Goodwill
Community banking
Goodwill [Roll Forward]
Beginning balance	331,752,000
Goodwill Acquired	16,718,000
Impairment Loss	0
Goodwill Adjustments	0
Ending balance	348,470,000
Specialty finance
Goodwill [Roll Forward]
Beginning balance	41,768,000
Goodwill Acquired	0
Impairment Loss	0
Goodwill Adjustments	(2,155,000)
Ending balance	39,613,000
Wealth management
Goodwill [Roll Forward]
Beginning balance	32,114,000
Goodwill Acquired	0
Impairment Loss	0
Goodwill Adjustments	0
Ending balance	$ 32,114,000

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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-Publisher FASB

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- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-SubTopic 20

-Section 50

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- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

Amount of increase (decrease) from foreign currency translation adjustments and purchase accounting adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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