Goodwill And Other Intangible Assets (Goodwill Assets by Business Segment) (Detail) $ in Thousands	9 Months Ended
Sep. 30, 2021 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 645,707
Goodwill Acquired	0
Impairment Loss	0
Goodwill Adjustments	85
Ending balance	645,792
Community banking
Goodwill [Roll Forward]
Beginning balance	536,396
Goodwill Acquired	0
Impairment Loss	0
Goodwill Adjustments	0
Ending balance	536,396
Specialty finance
Goodwill [Roll Forward]
Beginning balance	39,938
Goodwill Acquired	0
Impairment Loss	0
Goodwill Adjustments	85
Ending balance	40,023
Wealth management
Goodwill [Roll Forward]
Beginning balance	69,373
Goodwill Acquired	0
Impairment Loss	0
Goodwill Adjustments	0
Ending balance	$ 69,373

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.

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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.

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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.

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