LOAN LOSS ALLOWANCE - Allowance Activity (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2017
Activity in the allowance for loan losses
Balance at beginning of period	$ 51,834
Provision/(releases) for loan losses	5,575	$ 5,095
Balance at end of period	53,859
Allowance For Loan Losses
Total	51,834		$ 53,859	$ 51,834
Business Activities Loans
Activity in the allowance for loan losses
Balance at beginning of period	45,920	39,229
Charged-off loans	1,936	2,316
Recoveries on charged-off loans	141	175
Provision/(releases) for loan losses	3,152	4,375
Balance at end of period	47,277	41,463
Allowance For Loan Losses
Individually evaluated for impairment			609	460
Collectively evaluated for impairment			46,668	45,460
Total	45,920	39,229	47,277	45,920
Business Activities Loans \| Commercial real estate
Activity in the allowance for loan losses
Balance at beginning of period	16,843	16,498
Charged-off loans	106	124
Recoveries on charged-off loans	23	58
Provision/(releases) for loan losses	1,081	(152)
Balance at end of period	17,841	16,280
Allowance For Loan Losses
Individually evaluated for impairment			174	229
Collectively evaluated for impairment			17,667	16,614
Total	16,843	16,498	17,841	16,843
Business Activities Loans \| Commercial and industrial loans
Activity in the allowance for loan losses
Balance at beginning of period	13,850	9,447
Charged-off loans	890	1,270
Recoveries on charged-off loans	44	16
Provision/(releases) for loan losses	225	3,657
Balance at end of period	13,229	11,850
Allowance For Loan Losses
Individually evaluated for impairment			296	66
Collectively evaluated for impairment			12,933	13,784
Total	13,850	9,447	13,229	13,850
Business Activities Loans \| Residential mortgages
Activity in the allowance for loan losses
Balance at beginning of period	9,420	7,805
Charged-off loans	0	235
Recoveries on charged-off loans	0	15
Provision/(releases) for loan losses	(822)	278
Balance at end of period	8,598	7,863
Allowance For Loan Losses
Individually evaluated for impairment			137	130
Collectively evaluated for impairment			8,461	9,290
Total	9,420	7,805	8,598	9,420
Business Activities Loans \| Consumer
Activity in the allowance for loan losses
Balance at beginning of period	5,807	5,479
Charged-off loans	940	687
Recoveries on charged-off loans	74	86
Provision/(releases) for loan losses	2,668	592
Balance at end of period	7,609	5,470
Allowance For Loan Losses
Individually evaluated for impairment			2	35
Collectively evaluated for impairment			7,607	5,772
Total	5,807	5,479	7,609	5,807
Acquired Loans
Activity in the allowance for loan losses
Balance at beginning of period	5,914	4,769
Charged-off loans	1,855	1,307
Recoveries on charged-off loans	100	159
Provision/(releases) for loan losses	2,423	720
Balance at end of period	6,582	4,341
Allowance For Loan Losses
Individually evaluated for impairment			580	111
Collectively evaluated for impairment			6,002	5,803
Total	5,914	4,769	6,582	5,914
Acquired Loans \| Commercial real estate
Activity in the allowance for loan losses
Balance at beginning of period	3,856	2,303
Charged-off loans	740	577
Recoveries on charged-off loans	6	10
Provision/(releases) for loan losses	873	392
Balance at end of period	3,995	2,128
Allowance For Loan Losses
Individually evaluated for impairment			41	56
Collectively evaluated for impairment			3,954	3,800
Total	3,856	2,303	3,995	3,856
Acquired Loans \| Commercial and industrial loans
Activity in the allowance for loan losses
Balance at beginning of period	1,125	1,164
Charged-off loans	155	436
Recoveries on charged-off loans	29	55
Provision/(releases) for loan losses	244	271
Balance at end of period	1,243	1,054
Allowance For Loan Losses
Individually evaluated for impairment			3	1
Collectively evaluated for impairment			1,240	1,124
Total	1,125	1,164	1,243	1,125
Acquired Loans \| Residential mortgages
Activity in the allowance for loan losses
Balance at beginning of period	598	766
Charged-off loans	431	143
Recoveries on charged-off loans	25	39
Provision/(releases) for loan losses	854	44
Balance at end of period	1,046	706
Allowance For Loan Losses
Individually evaluated for impairment			506	9
Collectively evaluated for impairment			540	589
Total	598	766	1,046	598
Acquired Loans \| Consumer
Activity in the allowance for loan losses
Balance at beginning of period	335	536
Charged-off loans	529	151
Recoveries on charged-off loans	40	55
Provision/(releases) for loan losses	452	13
Balance at end of period	298	453
Allowance For Loan Losses
Individually evaluated for impairment			30	45
Collectively evaluated for impairment			268	290
Total	$ 335	$ 536	$ 298	$ 335

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

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