PARENT COMPANY CONDENSED FINANCIAL STATEMENTS: (Details 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 7,114	$ 8,398	$ 6,923	$ 7,761	$ 9,181	$ 8,272	$ 8,488	$ 7,831	$ 30,196	$ 33,772	$ 31,534
Adjustments to reconcile net income to net cash provided by operating activities:
Contribution of shares to ESOP									1,294	1,253	1,218
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchases of treasury stock									(8,698)	(14,633)	(162)
Dividends paid									(12,632)	(12,949)	(12,766)
NET CHANGE IN CASH AND CASH EQUIVALENTS									10,593	7,069	(16,197)
CASH AND DUE FROM BANKS, BEGINNING OF YEAR				78,102				71,033	78,102	71,033	87,230
CASH AND DUE FROM BANKS, END OF YEAR	88,695				78,102				88,695	78,102	71,033
Supplemental disclosures of cash flow information:
Interest									4,237	5,527	9,375
Income Taxes									12,869	9,354	13,822
Parent
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income									30,196	33,772	31,534
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization									203	196	173
Equity in undistributed earnings									(11,503)	(8,109)	(25,385)
Contribution of shares to ESOP									1,294	1,253	1,218
Securities (gains) losses									0	0	(420)
Restricted stock compensation									684	1,072	611
Increase (decrease) in other liabilities									(1,524)	(473)	(512)
(Increase) decrease in other assets									188	155	485
NET CASH FROM OPERATING ACTIVITIES									19,538	27,866	7,704
CASH FLOWS FROM INVESTING ACTIVITIES:
Sales of securities available-for-sale									0	0	740
Purchase of furniture and fixtures									(65)	(1,299)	(5)
NET CASH FROM INVESTING ACTIVITIES									(65)	(1,299)	735
CASH FLOWS FROM FINANCING ACTIVITIES:
Purchases of treasury stock									(8,698)	(14,633)	0
Dividends paid									(12,632)	(12,949)	(12,766)
NET CASH FROM FINANCING ACTIVITES									(21,330)	(27,582)	(12,766)
NET CHANGE IN CASH AND CASH EQUIVALENTS									(1,857)	(1,015)	(4,327)
CASH AND DUE FROM BANKS, BEGINNING OF YEAR				$ 3,639				$ 4,654	3,639	4,654	8,981
CASH AND DUE FROM BANKS, END OF YEAR	$ 1,782				$ 3,639				1,782	3,639	4,654
Supplemental disclosures of cash flow information:
Interest									0	0	0
Income Taxes									$ 12,869	$ 9,354	$ 13,822