Goodwill and Other Intangible Assets (Gross Carrying Value And Accumulated Amortization Of Other Intangible Assets) (Detail) - USD ($) $ in Thousands	Jan. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Goodwill		$ 2,514,104	$ 538,373	$ 538,373
Gross Carrying Amount		261,037	47,625
Accumulated Amortization		(61,695)	(29,756)
Net Carrying Amount		199,342	17,869
Sterling And Bend
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, useful life	10 years
Core Deposits
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		146,037	26,625
Accumulated Amortization		(36,710)	(18,516)
Net Carrying Amount		109,327	8,109
Core Deposits | Sterling And Bend
Finite-Lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 119,100
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount		115,000	21,000
Accumulated Amortization		(24,985)	(11,240)
Net Carrying Amount		$ 90,015	$ 9,760
Customer Relationships | Sterling And Bend
Finite-Lived Intangible Assets [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 94,000