PARENT COMPANY CONDENSED FINANCIAL STATEMENTS: (Details 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 14,364	$ 12,257	$ 12,569	$ 9,682	$ 11,056	$ 11,313	$ 15,261	$ 8,953	$ 48,872	$ 46,583	$ 29,131
Adjustments to reconcile net income to net cash provided by operating activities:
Contribution of shares to ESOP									1,251	1,087	1,062
NET CASH FROM OPERATING ACTIVITIES									49,901	57,448	50,135
CASH FLOWS FROM INVESTING ACTIVITIES:
NET CASH FROM INVESTING ACTIVITIES									(32,866)	(34,324)	(26,667)
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchases of treasury stock									(315)	(391)	(503)
Dividends paid									(12,648)	(12,496)	(30,556)
NET CASH FROM FINANCING ACTIVITIES									36,003	(22,843)	(24,373)
Supplemental disclosures of cash flow information:
Income Taxes									9,595	7,185	11,158
Parent
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income									48,872	46,583	29,131
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization									193	193	195
Equity in undistributed earnings									(29,568)	(34,092)	645
Contribution of shares to ESOP									1,251	1,087	1,062
Restricted stock compensation									801	745	706
Increase (decrease) in other liabilities									(2,150)	(585)	(247)
(Increase) decrease in other assets									1,187	(900)	0
NET CASH FROM OPERATING ACTIVITIES									20,586	13,031	31,492
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments to Acquire Interest in Subsidiaries and Affiliates									6,571	0	0
NET CASH FROM INVESTING ACTIVITIES									(6,571)	0	0
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchases of treasury stock									(315)	(391)	(503)
Dividends paid									(12,648)	(12,496)	(30,556)
NET CASH FROM FINANCING ACTIVITIES									(12,963)	(12,887)	(31,059)
NET CHANGE IN CASH AND CASH EQUIVALENTS									1,052	144	433
CASH AND DUE FROM BANKS, BEGINNING OF YEAR				$ 3,342				$ 3,198	3,342	3,198	2,765
CASH AND DUE FROM BANKS, END OF YEAR	$ 4,394				$ 3,342				4,394	3,342	3,198
Supplemental disclosures of cash flow information:
Interest									0	0	0
Income Taxes									$ 9,595	$ 7,185	$ 11,158