SECURITIES: (Details Textual)	2 Months Ended	12 Months Ended
	Mar. 07, 2018 USD ($)	Dec. 31, 2017 USD ($) cdo	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Securities pledged as collateral		$ 423,900,000	$ 391,100,000
Gain on sale of investments		185,000	39,000
Loss on sale of investments		$ 126,000	6,000
Number of investment securities with an amortized cost greater than fair value (investments)		239
Cumulative OTTI charges		$ 7,132,000	13,974,000	$ 13,995,000	$ 14,050,000
Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities		141,819,000	168,506,000	$ 150,315,000
Amortized Cost		811,369,000	855,521,000
Securities available-for-sale		814,931,000	853,725,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		$ 9,535,000	$ 14,414,000
Standard Poors | Minimum
Schedule of Available-for-sale Securities [Line Items]
Credit quality indicator pricing		67.64
Standard Poors | Maximum
Schedule of Available-for-sale Securities [Line Items]
Credit quality indicator pricing		79.33
Moody Investor Service | Minimum
Schedule of Available-for-sale Securities [Line Items]
Credit quality indicator pricing		19.53
Moody Investor Service | Maximum
Schedule of Available-for-sale Securities [Line Items]
Credit quality indicator pricing		49.45
Other Than Temporarily Impaired Cdo [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of CDO's | cdo		2
Contractual balance		$ 18,400,000
Reduced balance		14,600,000
Interest payment received		2,600,000
Cumulative OTTI charges		7,200,000
Other comprehensive income net		$ 6,000,000
Base discount rate, which is subject to an additional margin		3 month LIBOR
Other Than Temporarily Impaired Cdo [Member] | Minimum
Schedule of Available-for-sale Securities [Line Items]
Severity of OTTI (as a percent)		28.00%
Other Than Temporarily Impaired Cdo [Member] | Maximum
Schedule of Available-for-sale Securities [Line Items]
Severity of OTTI (as a percent)		80.00%
London Interbank Offered Rate (LIBOR) [Member] | Other Than Temporarily Impaired Cdo [Member]
Schedule of Available-for-sale Securities [Line Items]
Available For Sale Securities Present Value Of Future Cash Flows Discount Rate, Basis Point Spread on Variable Rate Basis, Minimum		1.60%
Available For Sale Securities Present Value Of Future Cash Flows Discount Rate, Basis Point Spread on Variable Rate Basis, Maximum		1.80%
Subsequent Event [Member]
Schedule of Available-for-sale Securities [Line Items]
Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities	$ 3,100,000