Goodwill and Other Acquisition-Related Intangible Assets (Goodwill Assets by Business Segment) (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 653,524
Goodwill Acquired	2,622
Impairment Loss	0
Goodwill Adjustments	528
Ending balance	656,674
Community banking
Goodwill [Roll Forward]
Beginning balance	545,671
Goodwill Acquired	0
Impairment Loss	0
Goodwill Adjustments	0
Ending balance	545,671
Specialty finance
Goodwill [Roll Forward]
Beginning balance	38,480
Goodwill Acquired	0
Impairment Loss	0
Goodwill Adjustments	528
Ending balance	39,008
Wealth management
Goodwill [Roll Forward]
Beginning balance	69,373
Goodwill Acquired	2,622
Impairment Loss	0
Goodwill Adjustments	0
Ending balance	$ 71,995