ACQUISITION OF FIRST NATIONAL BANKSHARES CORPORATION (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2016 USD ($)	Jan. 15, 2016 USD ($) Branch shares	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Business Acquisition [Line Items]
Goodwill	$ 35,371		$ 33,796	$ 33,796	$ 29,875
Estimated amortization of core deposit intangible [Abstract]
2016	974
2017	765
2018	656
2019	475
2020	473
Thereafter	1,006
First National Bankshares [Member]
Business Acquisition [Line Items]
Merger consideration entitled to common stock (in shares) | shares		1.859
Goodwill	$ 1,570	$ 3,320
Number of branch locations acquired | Branch		6
Net assets acquired via acquisition [Abstract]
Cash and due from banks		$ 11,912
Time deposits with other banks		4,473
Securities available for sale		76,612
Loans, net		132,798
Premises and equipment		5,839
Goodwill and other intangible assets		4,883
Other assets		824
Total assets acquired		237,341
Deposits		(205,174)
Repurchase agreements		(2,168)
FHLB borrowings		(1,347)
Subordinated debt		(5,307)
Other liabilities		(1,304)
Total liabilities assumed		(215,300)
Net assets acquired		22,041
Fair value of non-impaired loans acquired		125,669
Gross contractual amounts receivable		127,347
First National Bankshares [Member] | Core Deposits [Member]
Business Acquisition [Line Items]
Estimated useful life	10 years
Estimated amortization of core deposit intangible [Abstract]
2016		455
2017		428
2018		364
2019		309
2020		289
Thereafter		1,463
Total intangible acquired		3,308
First National Bankshares [Member] | As Initially Reported [Member]
Net assets acquired via acquisition [Abstract]
Cash and due from banks		11,912
Time deposits with other banks		4,473
Securities available for sale		76,612
Loans, net		132,954
Premises and equipment		4,606
Goodwill and other intangible assets		5,176
Other assets		1,764
Total assets acquired		237,497
Deposits		(205,174)
Repurchase agreements		(2,168)
FHLB borrowings		(1,347)
Subordinated debt		(5,307)
Other liabilities		(1,460)
Total liabilities assumed		(215,456)
Net assets acquired		22,041
First National Bankshares [Member] | Recast Adjustments During Measurement Period [Member]
Net assets acquired via acquisition [Abstract]
Cash and due from banks		0
Time deposits with other banks		0
Securities available for sale		0
Loans, net		(156)
Premises and equipment		1,233
Goodwill and other intangible assets		(293)
Other assets		(940)
Total assets acquired		(156)
Deposits		0
Repurchase agreements		0
FHLB borrowings		0
Subordinated debt		0
Other liabilities		156
Total liabilities assumed		156
Net assets acquired		$ 0