Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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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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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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

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Loans and Leases (Allowance For Loan And Lease Losses By Portfolio Segment) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 211,389	$ 205,349	$ 212,353	$ 199,994
Provision (benefit) charged to expense	11,900	10,500	20,500	21,500
Charge-offs	(14,382)	(11,398)	(27,416)	(19,008)
Recoveries	2,764	2,871	6,234	4,836
Balance, end of period	211,389	205,349	212,353	199,994	$ 211,671	$ 212,353	$ 207,322
ALLL, Individually evaluated for impairment					14,781		13,914
ALLL, Collectively evaluated for impairment					196,890		193,408
Loan and lease balances, Individually evaluated for impairment					253,247		257,205
Loan and lease balances, Collectively evaluated for impairment					19,016,636		17,768,791
Loans and leases					19,269,883	18,465,489	18,025,996
Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	20,413	18,777	19,599	19,058
Provision (benefit) charged to expense	2,667	659	3,554	909
Charge-offs	(2,154)	(754)	(2,405)	(1,671)
Recoveries	295	325	473	711
Balance, end of period	20,413	18,777	19,599	19,058	21,221	19,599	19,007
ALLL, Individually evaluated for impairment					3,969		4,330
ALLL, Collectively evaluated for impairment					17,252		14,677
Loan and lease balances, Individually evaluated for impairment					100,168		109,636
Loan and lease balances, Collectively evaluated for impairment					4,618,536		4,345,944
Loans and leases					4,718,704	4,416,637	4,455,580
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	26,919	34,239	28,681	36,190
Provision (benefit) charged to expense	1,313	813	1,036	2,493
Charge-offs	(4,098)	(4,907)	(8,071)	(9,981)
Recoveries	1,972	1,614	4,460	3,057
Balance, end of period	26,919	34,239	28,681	36,190	26,106	28,681	31,759
ALLL, Individually evaluated for impairment					1,292		1,498
ALLL, Collectively evaluated for impairment					24,814		30,261
Loan and lease balances, Individually evaluated for impairment					37,332		41,636
Loan and lease balances, Collectively evaluated for impairment					2,263,959		2,444,059
Loans and leases					2,301,291	2,396,704	2,485,695
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	100,174	95,573	98,793	89,533
Provision (benefit) charged to expense	3,391	4,490	11,618	11,910
Charge-offs	(5,218)	(5,632)	(12,851)	(7,129)
Recoveries	453	909	1,240	1,026
Balance, end of period	100,174	95,573	98,793	89,533	98,800	98,793	95,340
ALLL, Individually evaluated for impairment					8,696		6,007
ALLL, Collectively evaluated for impairment					90,104		89,333
Loan and lease balances, Individually evaluated for impairment					97,919		87,071
Loan and lease balances, Collectively evaluated for impairment					6,422,034		5,894,485
Loans and leases					6,519,953	6,216,606	5,981,556
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	58,893	51,436	60,151	49,407
Provision (benefit) charged to expense	4,615	4,428	4,324	6,532
Charge-offs	(2,473)	(40)	(3,446)	(117)
Recoveries	33	9	39	11
Balance, end of period	58,893	51,436	60,151	49,407	61,068	60,151	55,833
ALLL, Individually evaluated for impairment					656		2,061
ALLL, Collectively evaluated for impairment					60,412		53,772
Loan and lease balances, Individually evaluated for impairment					13,879		12,677
Loan and lease balances, Collectively evaluated for impairment					5,210,503		4,567,523
Loans and leases					5,224,382	4,927,145	4,580,200
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	4,990	5,324	5,129	5,806
Provision (benefit) charged to expense	(86)	110	(32)	(344)
Charge-offs	(439)	(65)	(643)	(110)
Recoveries	11	14	22	31
Balance, end of period	$ 4,990	$ 5,324	$ 5,129	$ 5,806	4,476	5,129	5,383
ALLL, Individually evaluated for impairment					168		18
ALLL, Collectively evaluated for impairment					4,308		5,365
Loan and lease balances, Individually evaluated for impairment					3,949		6,185
Loan and lease balances, Collectively evaluated for impairment					501,604		516,780
Loans and leases					$ 505,553	$ 508,397	$ 522,965