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		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	$ 211,671	$ 207,322	$ 212,353	$ 199,994
Provision (benefit) charged to expense	11,300	10,500	31,800	32,000
Charge-offs	(15,960)	(8,535)	(43,376)	(27,543)
Recoveries	2,141	2,545	8,375	7,381
Balance, end of period	211,671	207,322	212,353	199,994	$ 209,152	$ 212,353	$ 211,832
ALLL, Individually evaluated for impairment					20,366		17,797
ALLL, Collectively evaluated for impairment					188,786		194,035
Loan and lease balances, Individually evaluated for impairment					270,631		266,017
Loan and lease balances, Collectively evaluated for impairment					19,281,015		18,055,002
Loans and leases					19,551,646	18,465,489	18,321,019
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	98,800	95,340	98,793	89,533
Provision (benefit) charged to expense	11,202	5,686	22,820	17,596
Charge-offs	(11,255)	(740)	(24,106)	(7,869)
Recoveries	124	431	1,364	1,457
Balance, end of period	98,800	95,340	98,793	89,533	98,871	98,793	100,717
ALLL, Individually evaluated for impairment					14,555		10,491
ALLL, Collectively evaluated for impairment					84,316		90,226
Loan and lease balances, Individually evaluated for impairment					117,418		104,353
Loan and lease balances, Collectively evaluated for impairment					6,370,638		6,070,043
Loans and leases					6,488,056	6,216,606	6,174,396
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	61,068	55,833	60,151	49,407
Provision (benefit) charged to expense	(423)	4,146	3,901	10,678
Charge-offs	(32)	(1,922)	(3,478)	(2,039)
Recoveries	3	143	42	154
Balance, end of period	61,068	55,833	60,151	49,407	60,616	60,151	58,200
ALLL, Individually evaluated for impairment					735		1,544
ALLL, Collectively evaluated for impairment					59,881		56,656
Loan and lease balances, Individually evaluated for impairment					16,224		9,767
Loan and lease balances, Collectively evaluated for impairment					5,381,860		4,761,558
Loans and leases					5,398,084	4,927,145	4,771,325
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	4,476	5,383	5,129	5,806
Provision (benefit) charged to expense	(176)	(213)	(208)	(557)
Charge-offs	(36)	(136)	(679)	(246)
Recoveries	49	11	71	42
Balance, end of period	4,476	5,383	5,129	5,806	4,313	5,129	5,045
ALLL, Individually evaluated for impairment					177		15
ALLL, Collectively evaluated for impairment					4,136		5,030
Loan and lease balances, Individually evaluated for impairment					5,487		6,489
Loan and lease balances, Collectively evaluated for impairment					516,341		512,565
Loans and leases					521,828	508,397	519,054
Residential Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	21,221	19,007	19,599	19,058
Provision (benefit) charged to expense	(689)	407	2,865	1,316
Charge-offs	(872)	(874)	(3,277)	(2,545)
Recoveries	356	133	829	844
Balance, end of period	21,221	19,007	19,599	19,058	20,016	19,599	18,673
ALLL, Individually evaluated for impairment					3,625		4,319
ALLL, Collectively evaluated for impairment					16,391		14,354
Loan and lease balances, Individually evaluated for impairment					95,666		105,600
Loan and lease balances, Collectively evaluated for impairment					4,778,060		4,309,463
Loans and leases					4,873,726	4,416,637	4,415,063
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance, beginning of period	26,106	31,759	28,681	36,190
Provision (benefit) charged to expense	1,386	474	2,422	2,967
Charge-offs	(3,765)	(4,863)	(11,836)	(14,844)
Recoveries	1,609	1,827	6,069	4,884
Balance, end of period	$ 26,106	$ 31,759	$ 28,681	$ 36,190	25,336	28,681	29,197
ALLL, Individually evaluated for impairment					1,274		1,428
ALLL, Collectively evaluated for impairment					24,062		27,769
Loan and lease balances, Individually evaluated for impairment					35,836		39,808
Loan and lease balances, Collectively evaluated for impairment					2,234,116		2,401,373
Loans and leases					$ 2,269,952	$ 2,396,704	$ 2,441,181