Loans and Leases (Allowance For Loan And Lease Losses By Portfolio Segment) (Detail) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended
Jan. 31, 2022	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period				$ 301,187	$ 359,431
Initial allowance for PCD loans and leases				88,045	0
Provision (benefit)		$ 11,728	$ (21,574)	200,796	(47,333)
Charge-offs				(32,021)	(12,697)
Recoveries				13,492	8,544
Balance, end of period		571,499	307,945	571,499	307,945
ALLL, Individually evaluated for impairment		43,297	16,097	43,297	16,097
ALLL, Collectively evaluated for impairment		528,202	291,848	528,202	291,848
PCD loans \| Sterling
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs	$ (48,300)
Commercial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period				257,877	312,244
Initial allowance for PCD loans and leases				78,376	0
Provision (benefit)		12,041	(21,077)	196,368	(44,730)
Charge-offs				(30,005)	(6,915)
Recoveries				9,129	2,472
Balance, end of period		511,745	263,071	511,745	263,071
ALLL, Individually evaluated for impairment		38,847	11,537	38,847	11,537
ALLL, Collectively evaluated for impairment		472,898	251,534	472,898	251,534
Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period				43,310	47,187
Initial allowance for PCD loans and leases				9,669	0
Provision (benefit)		(313)	(497)	4,428	(2,603)
Charge-offs				(2,016)	(5,782)
Recoveries				4,363	6,072
Balance, end of period		59,754	44,874	59,754	44,874
ALLL, Individually evaluated for impairment		4,450	4,560	4,450	4,560
ALLL, Collectively evaluated for impairment		$ 55,304	$ 40,314	$ 55,304	$ 40,314

Amount excluding accrued interest, of allowance for credit loss on financing receivable.

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Amount of increase in allowance for credit loss on financing receivable purchased with credit deterioration.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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Amount of increase in allowance for credit loss on financing receivable from recovery.

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Amount of expense related to estimated loss from loan and lease transactions.

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