LOANS - Loans Evaluated for Impairment (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Loans receivable: balance at end of period
Total	$ 2,428,862	$ 1,129,064
Commercial real estate
Loans receivable: balance at end of period
Total	793,572	418,119
Commercial and industrial
Loans receivable: balance at end of period
Total	357,072	151,240
Residential real estate
Loans receivable: balance at end of period
Total	1,152,628	506,612
Consumer
Loans receivable: balance at end of period
Total	125,590	53,093
Business Activities Loans
Loans receivable: balance at end of period
Individually evaluated for impairment	4,535	6,709
Collectively evaluated	1,354,981	1,122,355
Total	1,359,516	1,129,064
Business Activities Loans \| Commercial real estate
Loans receivable: balance at end of period
Individually evaluated for impairment	2,585	4,481
Collectively evaluated	486,954	413,638
Total	489,539	418,119
Business Activities Loans \| Commercial and industrial
Loans receivable: balance at end of period
Individually evaluated for impairment	138	486
Collectively evaluated	243,307	150,754
Total	243,445	151,240
Business Activities Loans \| Residential real estate
Loans receivable: balance at end of period
Individually evaluated for impairment	1,744	1,709
Collectively evaluated	566,533	504,903
Total	568,277	506,612
Business Activities Loans \| Consumer
Loans receivable: balance at end of period
Individually evaluated for impairment	68	33
Collectively evaluated	58,187	53,060
Total	58,255	53,093
Acquired Loans
Loans receivable: balance at end of period
Individually evaluated for impairment	1,305
Purchased Credit Impaired	14,376
Collectively evaluated	1,053,665
Total	1,069,346	0
Acquired Loans \| Commercial real estate
Loans receivable: balance at end of period
Individually evaluated for impairment	408
Purchased Credit Impaired	10,018
Collectively evaluated	293,607
Total	304,033	0
Acquired Loans \| Commercial and industrial
Loans receivable: balance at end of period
Individually evaluated for impairment	470
Purchased Credit Impaired	917
Collectively evaluated	112,240
Total	113,627	0
Acquired Loans \| Residential real estate
Loans receivable: balance at end of period
Individually evaluated for impairment	271
Purchased Credit Impaired	3,398
Collectively evaluated	580,682
Total	584,351	0
Acquired Loans \| Consumer
Loans receivable: balance at end of period
Individually evaluated for impairment	156
Purchased Credit Impaired	43
Collectively evaluated	67,136
Total	$ 67,335	$ 0

Financing Receivable, Purchased Credit-Impaired Loans

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- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

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- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

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