Goodwill and Other Intangible Assets (Gross Carrying Value And Accumulated Amortization Of Other Intangible Assets) (Detail) - USD ($) $ in Thousands	Jan. 11, 2023	Jun. 30, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		$ 301,037	$ 261,037
Accumulated Amortization		80,385	61,695
Net Carrying Amount		220,652	199,342
Core deposits
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		146,037	146,037
Accumulated Amortization		45,623	36,710
Net Carrying Amount		100,414	109,327
Customer relationships (1)
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		151,000	115,000
Accumulated Amortization		34,362	24,985
Net Carrying Amount		116,638	90,015
Customer relationships (1) | interLINK
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, useful life	10 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets	$ 36,000
Noncompete Agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		4,000	0
Accumulated Amortization		400	0
Net Carrying Amount		$ 3,600	$ 0
Noncompete Agreements | interLINK
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, useful life	5 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets	$ 4,000