LOANS AND LEASES - Age Analysis of Past Due Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	$ 20,533,298	$ 14,896,943
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	8,822,929	5,435,162
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	3,910,927	3,042,781
Commercial Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	226,483	196,636
Total Commercial Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	12,960,339	8,674,579
Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	1,949,979	1,844,399
Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	2,429,843	1,844,574
Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	1,374,524	1,196,313
Consumer Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	1,788,534	1,301,200
Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	30,079	35,878
Originated Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	84,651	62,083
Past Due	136,783	131,046
Current	13,707,087	12,416,941
Total Loans	13,843,870	12,547,987
Originated Loans and Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	24,624	20,114
Past Due	28,796	28,567
Current	4,581,608	4,067,250
Total Loans	4,610,404	4,095,817
Originated Loans and Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	40,210	24,141
Past Due	45,461	40,163
Current	2,989,544	2,671,723
Total Loans	3,035,005	2,711,886
Originated Loans and Leases [Member] | Commercial Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	1,507	3,429
Past Due	2,809	4,403
Current	223,674	192,233
Total Loans	226,483	196,636
Originated Loans and Leases [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	66,341	47,684
Past Due	77,066	73,133
Current	7,794,826	6,931,206
Total Loans	7,871,892	7,004,339
Originated Loans and Leases [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	8,285	6,484
Past Due	22,491	21,443
Current	1,741,605	1,743,814
Total Loans	1,764,096	1,765,257
Originated Loans and Leases [Member] | Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	5,119	3,316
Past Due	20,177	16,924
Current	1,663,206	1,429,852
Total Loans	1,683,383	1,446,776
Originated Loans and Leases [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	1,744	1,983
Past Due	9,383	11,808
Current	1,364,987	1,184,302
Total Loans	1,374,370	1,196,110
Originated Loans and Leases [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	2,162	1,616
Past Due	5,872	6,257
Current	1,114,178	1,093,370
Total Loans	1,120,050	1,099,627
Originated Loans and Leases [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	1,000	1,000
Past Due	1,794	1,481
Current	28,285	34,397
Total Loans	30,079	35,878
Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	10,652	3,396
Past Due	159,017	68,130
Current	6,848,844	2,430,340
Discount	(318,433)	(149,514)
Total Loans	6,689,428	2,348,956
Acquired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	3,478	949
Past Due	92,685	34,340
Current	4,326,243	1,384,752
Discount	(206,403)	(79,747)
Total Loans	4,212,525	1,339,345
Acquired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	6,676	2,111
Past Due	18,450	6,842
Current	913,794	353,494
Discount	(56,322)	(29,441)
Total Loans	875,922	330,895
Acquired Loans [Member] | Commercial Leases [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]
Non- Accrual	10,154	3,060
Past Due	111,135	41,182
Current	5,240,037	1,738,246
Discount	(262,725)	(109,188)
Total Loans	5,088,447	1,670,240
Acquired Loans [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	0	0
Past Due	3,974	3,661
Current	180,278	73,479
Discount	1,631	2,002
Total Loans	185,883	79,142
Acquired Loans [Member] | Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	0	0
Past Due	30,525	19,244
Current	758,511	416,561
Discount	(42,576)	(38,007)
Total Loans	746,460	397,798
Acquired Loans [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	0	0
Past Due	1	23
Current	37	96
Discount	116	84
Total Loans	154	203
Acquired Loans [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Non- Accrual	498	336
Past Due	13,382	4,020
Current	669,981	201,958
Discount	(14,879)	(4,405)
Total Loans	668,484	201,573
Acquired Loans [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Loans	0	0
30-89 Days Past Due [Member] | Originated Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	43,684	59,850
30-89 Days Past Due [Member] | Originated Loans and Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,171	8,452
30-89 Days Past Due [Member] | Originated Loans and Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,248	16,019
30-89 Days Past Due [Member] | Originated Loans and Leases [Member] | Commercial Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,302	973
30-89 Days Past Due [Member] | Originated Loans and Leases [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10,721	25,444
30-89 Days Past Due [Member] | Originated Loans and Leases [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	10,052	10,573
30-89 Days Past Due [Member] | Originated Loans and Leases [Member] | Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12,698	10,594
30-89 Days Past Due [Member] | Originated Loans and Leases [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	7,174	9,312
30-89 Days Past Due [Member] | Originated Loans and Leases [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,527	3,529
30-89 Days Past Due [Member] | Originated Loans and Leases [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	512	398
30-89 Days Past Due [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	86,943	24,210
30-89 Days Past Due [Member] | Acquired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	52,011	9,501
30-89 Days Past Due [Member] | Acquired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	5,552	1,789
30-89 Days Past Due [Member] | Acquired Loans [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	57,563	11,290
30-89 Days Past Due [Member] | Acquired Loans [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,086	2,317
30-89 Days Past Due [Member] | Acquired Loans [Member] | Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	18,141	8,428
30-89 Days Past Due [Member] | Acquired Loans [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	19
30-89 Days Past Due [Member] | Acquired Loans [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	9,153	2,156
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Originated Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	8,448	9,113
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Originated Loans and Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1	1
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Originated Loans and Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	3	3
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Originated Loans and Leases [Member] | Commercial Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	0	1
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Originated Loans and Leases [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4	5
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Originated Loans and Leases [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	4,154	4,386
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Originated Loans and Leases [Member] | Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,360	3,014
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Originated Loans and Leases [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	465	513
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Originated Loans and Leases [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,183	1,112
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Originated Loans and Leases [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	282	83
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	61,422	40,524
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Acquired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	37,196	23,890
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Acquired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	6,222	2,942
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Acquired Loans [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	43,418	26,832
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Acquired Loans [Member] | Direct Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1,888	1,344
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Acquired Loans [Member] | Residential Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	12,384	10,816
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Acquired Loans [Member] | Indirect Installment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	1	4
Equal to Greater than 90 Days Past Due and Still Accruing [Member] | Acquired Loans [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 3,731	$ 1,528