LOANS - Contractual Aging of Recorded Investment in Past Due Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	$ 16,979	$ 18,071
Current	3,311,120	2,857,695
Total Financing Receivables	3,330,075	2,879,536
Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	1,703	2,281
Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	79	1,489
Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	194	0
Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	10,541	11,023
Current	2,711,683	2,412,629
Total Financing Receivables	2,722,866	2,425,850
Portfolio Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	563	1,707
Portfolio Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	79	491
Portfolio Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Purchased Unimpaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	2,677	2,763
Current	590,255	436,540
Total Financing Receivables	594,077	440,690
Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	951	574
Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	813
Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	194	0
Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	3,761	4,285
Current	9,182	8,526
Total Financing Receivables	13,132	12,996
Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	189	0
Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	185
Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial and financial [Member] | Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	49
Current	393,088	308,652
Total Financing Receivables	393,213	308,731
Commercial and financial [Member] | Portfolio Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	125	30
Commercial and financial [Member] | Portfolio Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial and financial [Member] | Portfolio Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial and financial [Member] | Purchased Unimpaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	347	197
Current	70,210	60,353
Total Financing Receivables	71,071	60,917
Commercial and financial [Member] | Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	514	39
Commercial and financial [Member] | Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	328
Commercial and financial [Member] | Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial and financial [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
Current	854	941
Total Financing Receivables	854	941
Commercial and financial [Member] | Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial and financial [Member] | Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial and financial [Member] | Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Consumer [Member] | Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	133	170
Current	174,132	152,669
Total Financing Receivables	174,376	152,927
Consumer [Member] | Portfolio Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	97	29
Consumer [Member] | Portfolio Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	14	59
Consumer [Member] | Portfolio Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Consumer [Member] | Purchased Unimpaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
Current	4,219	981
Total Financing Receivables	4,219	1,018
Consumer [Member] | Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	37
Consumer [Member] | Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Consumer [Member] | Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Consumer [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
Current	0	0
Total Financing Receivables	0	0
Consumer [Member] | Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Consumer [Member] | Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Consumer [Member] | Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial real estate [Member] | Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	1,209	1,784
Current	1,097,425	1,039,882
Total Financing Receivables	1,098,634	1,041,915
Commercial real estate [Member] | Portfolio Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	78
Commercial real estate [Member] | Portfolio Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	171
Commercial real estate [Member] | Portfolio Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial real estate [Member] | Purchased Unimpaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	743	1,272
Current	352,791	302,318
Total Financing Receivables	353,971	304,420
Commercial real estate [Member] | Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	437	345
Commercial real estate [Member] | Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	485
Commercial real estate [Member] | Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial real estate [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	3,761	4,285
Current	7,702	6,972
Total Financing Receivables	11,463	11,257
Commercial real estate [Member] | Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial real estate [Member] | Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Commercial real estate [Member] | Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	544	438
Current	180,517	137,042
Total Financing Receivables	181,334	137,480
Construction and land development [Member] | Portfolio Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	273	0
Construction and land development [Member] | Portfolio Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Portfolio Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Purchased Unimpaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	125	32
Current	49,002	22,490
Total Financing Receivables	49,127	22,522
Construction and land development [Member] | Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
Current	113	114
Total Financing Receivables	113	114
Construction and land development [Member] | Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Construction and land development [Member] | Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Residential real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Financing Receivables	991,144	836,787
Residential real estate [Member] | Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	8,655	8,582
Current	865,965	773,877
Total Financing Receivables	874,753	784,290
Residential real estate [Member] | Portfolio Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	68	1,570
Residential real estate [Member] | Portfolio Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	65	261
Residential real estate [Member] | Portfolio Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Residential real estate [Member] | Purchased Unimpaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	1,462	1,262
Current	114,033	50,398
Total Financing Receivables	115,689	51,813
Residential real estate [Member] | Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	153
Residential real estate [Member] | Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Residential real estate [Member] | Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	194	0
Residential real estate [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
Current	513	499
Total Financing Receivables	702	684
Residential real estate [Member] | Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	189	0
Residential real estate [Member] | Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	185
Residential real estate [Member] | Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Other [Member] | Portfolio Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
Current	556	507
Total Financing Receivables	556	507
Other [Member] | Portfolio Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Other [Member] | Portfolio Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Other [Member] | Portfolio Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Other [Member] | Purchased Unimpaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
Current	0	0
Total Financing Receivables	0	0
Other [Member] | Purchased Unimpaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Other [Member] | Purchased Unimpaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Other [Member] | Purchased Unimpaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Other [Member] | Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual	0	0
Current	0	0
Total Financing Receivables	0	0
Other [Member] | Purchased Credit Impaired Loans [Member] | Accruing 30-59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Other [Member] | Purchased Credit Impaired Loans [Member] | Accruing 60-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	0	0
Other [Member] | Purchased Credit Impaired Loans [Member] | Accruing Greater Than 90 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Financing Receivable, Recorded Investment, Past Due	$ 0	$ 0