LOANS AND LEASES - Age Analysis of Past Due Loans (Detail) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	$ 21,659,582	$ 20,998,766
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	8,834,322	8,741,864
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	4,301,387	4,170,667
Commercial Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	337,397	266,720
Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	43,351	17,063
Total Commercial Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	13,516,457	13,196,314
Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	1,892,080	1,905,535
Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	2,850,970	2,702,691
Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	1,746,509	1,448,433
Consumer Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	1,653,566	1,745,793
Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	8,143,125	7,802,452
Originated Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	115,485	134,911
Non- Accrual	59,953	63,644
Current	16,769,696	15,210,579
Total Loans	16,885,181	15,345,490
Loans sold	14,700
Originated Loans and Leases [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	48,305	62,146
Originated Loans and Leases [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	7,227	9,121
Originated Loans and Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	25,130	33,047
Non- Accrual	14,652	24,773
Current	5,729,237	5,141,736
Total Loans	5,754,367	5,174,783
Originated Loans and Leases [Member] | Commercial Real Estate [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10,476	8,273
Originated Loans and Leases [Member] | Commercial Real Estate [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2	1
Originated Loans and Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	29,033	26,028
Non- Accrual	23,367	17,077
Current	3,768,740	3,469,219
Total Loans	3,797,773	3,495,247
Originated Loans and Leases [Member] | Commercial and Industrial [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,663	8,948
Originated Loans and Leases [Member] | Commercial and Industrial [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3	3
Originated Loans and Leases [Member] | Commercial Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,079	2,997
Non- Accrual	1,218	1,574
Current	335,318	263,723
Total Loans	337,397	266,720
Originated Loans and Leases [Member] | Commercial Leases [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	861	1,382
Originated Loans and Leases [Member] | Commercial Leases [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	41
Originated Loans and Leases [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,367	1,236
Non- Accrual	1,000	1,000
Current	41,984	15,827
Total Loans	43,351	17,063
Originated Loans and Leases [Member] | Other [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	163	83
Originated Loans and Leases [Member] | Other [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	204	153
Originated Loans and Leases [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	57,609	63,308
Non- Accrual	40,237	44,424
Current	9,875,279	8,890,505
Total Loans	9,932,888	8,953,813
Originated Loans and Leases [Member] | Total Commercial Loans and Leases [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	17,163	18,686
Originated Loans and Leases [Member] | Total Commercial Loans and Leases [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	209	198
Originated Loans and Leases [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	20,747	26,554
Non- Accrual	7,402	8,896
Current	1,751,343	1,729,159
Total Loans	1,772,090	1,755,713
Originated Loans and Leases [Member] | Direct Installment [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	9,317	13,192
Originated Loans and Leases [Member] | Direct Installment [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,028	4,466
Originated Loans and Leases [Member] | Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	18,524	22,699
Non- Accrual	6,882	5,771
Current	2,279,034	2,013,527
Total Loans	2,297,558	2,036,226
Originated Loans and Leases [Member] | Residential Mortgages [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10,046	14,096
Originated Loans and Leases [Member] | Residential Mortgages [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,596	2,832
Originated Loans and Leases [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10,099	13,164
Non- Accrual	2,152	2,240
Current	1,736,253	1,435,104
Total Loans	1,746,352	1,448,268
Originated Loans and Leases [Member] | Indirect Installment [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	7,592	10,313
Originated Loans and Leases [Member] | Indirect Installment [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	355	611
Originated Loans and Leases [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	8,506	9,186
Non- Accrual	3,280	2,313
Current	1,127,787	1,142,284
Total Loans	1,136,293	1,151,470
Originated Loans and Leases [Member] | Consumer Lines of Credit [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,187	5,859
Originated Loans and Leases [Member] | Consumer Lines of Credit [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,039	1,014
Originated Loans and Leases [Member] | Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	57,876	71,603
Non- Accrual	19,716	19,220
Current	6,894,417	6,320,074
Total Loans	6,952,293	6,391,677
Originated Loans and Leases [Member] | Consumer Loan [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	31,142	43,460
Originated Loans and Leases [Member] | Consumer Loan [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	7,018	8,923
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	120,106	167,867
Non- Accrual	8,743	10,991
Current	4,894,298	5,768,610
(Discount) Premium	(240,003)	(283,201)
Total Loans	4,774,401	5,653,276
Loans sold	28,500
Acquired Loans [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	43,474	66,926
Acquired Loans [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	67,889	89,950
Acquired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	77,293	101,995
Non- Accrual	3,231	3,975
Current	3,181,557	3,657,152
(Discount) Premium	(178,895)	(192,066)
Total Loans	3,079,955	3,567,081
Acquired Loans [Member] | Commercial Real Estate [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	20,622	34,928
Acquired Loans [Member] | Commercial Real Estate [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	53,440	63,092
Acquired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	9,465	15,302
Non- Accrual	4,347	5,663
Current	526,830	698,265
(Discount) Premium	(32,681)	(38,147)
Total Loans	503,614	675,420
Acquired Loans [Member] | Commercial and Industrial [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,620	3,187
Acquired Loans [Member] | Commercial and Industrial [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,498	6,452
Acquired Loans [Member] | Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	86,758	117,297
Non- Accrual	7,578	9,638
Current	3,708,387	4,355,417
(Discount) Premium	(211,576)	(230,213)
Total Loans	3,583,569	4,242,501
Acquired Loans [Member] | Commercial Loans [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	22,242	38,115
Acquired Loans [Member] | Commercial Loans [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	56,938	69,544
Acquired Loans [Member] | Commercial Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	0	0
Acquired Loans [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	0	0
Acquired Loans [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	3,583,569	4,242,501
Acquired Loans [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,897	7,280
Non- Accrual	0	0
Current	115,496	141,386
(Discount) Premium	(403)	1,156
Total Loans	119,990	149,822
Acquired Loans [Member] | Direct Installment [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3,766	5,267
Acquired Loans [Member] | Direct Installment [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,131	2,013
Acquired Loans [Member] | Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	18,121	32,330
Non- Accrual	0	0
Current	552,387	675,499
(Discount) Premium	(17,096)	(41,364)
Total Loans	553,412	666,465
Acquired Loans [Member] | Residential Mortgages [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10,424	17,191
Acquired Loans [Member] | Residential Mortgages [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	7,697	15,139
Acquired Loans [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1	1
Non- Accrual	0	0
Current	1	10
(Discount) Premium	155	154
Total Loans	157	165
Acquired Loans [Member] | Indirect Installment [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	0
Acquired Loans [Member] | Indirect Installment [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1	1
Acquired Loans [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10,329	10,959
Non- Accrual	1,165	1,353
Current	518,027	596,298
(Discount) Premium	(11,083)	(12,934)
Total Loans	517,273	594,323
Acquired Loans [Member] | Consumer Lines of Credit [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	7,042	6,353
Acquired Loans [Member] | Consumer Lines of Credit [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,122	3,253
Acquired Loans [Member] | Consumer Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	33,348	50,570
Non- Accrual	1,165	1,353
Current	1,185,911	1,413,193
(Discount) Premium	(28,427)	(52,988)
Total Loans	1,190,832	1,410,775
Acquired Loans [Member] | Consumer Loan [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	21,232	28,811
Acquired Loans [Member] | Consumer Loan [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 10,951	$ 20,406