INVESTMENT AND MORTGAGE-BACKED SECURITIES, Reconciliation of Pre-Tax OTTI Charges Recognized (Details) - Pooled Bank Trust Preferred Securities [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
OTTI Credit and Non-Credit Losses Recognized in Earnings and AOCI [Abstract]
Cumulative pre-tax balance at the beginning of the period	$ 9,123	$ 9,261	$ 9,157	$ 9,295
Amortization of previously recognized OTTI	(35)	(34)	(69)	(68)
Cumulative pre-tax balance at end of the period	9,088	9,227	9,088	9,227
Credit Related OTTI [Member]
OTTI Credit and Non-Credit Losses Recognized in Earnings and AOCI [Abstract]
Cumulative pre-tax balance at the beginning of the period	8,587	8,691	8,613	8,717
Amortization of previously recognized OTTI	(26)	(26)	(52)	(52)
Cumulative pre-tax balance at end of the period	8,561	8,665	8,561	8,665
Non-Credit Related OTTI [Member]
OTTI Credit and Non-Credit Losses Recognized in Earnings and AOCI [Abstract]
Cumulative pre-tax balance at the beginning of the period	536	570	544	578
Amortization of previously recognized OTTI	(9)	(8)	(17)	(16)
Cumulative pre-tax balance at end of the period	$ 527	$ 562	$ 527	$ 562