DERIVATIVES AND HEDGING (Derivatives Not Designated as Hedging, by Balance Sheet Location) (Details) - USD ($) $ in Thousands		Sep. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value		$ 7,186	$ 8,330
Liability Derivatives, Fair Value		7,186	8,330
Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value		7,186	8,330
Liability Derivatives, Fair Value		7,186	8,330
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional/Contract Amount		490,199	423,424
Liability Derivatives, Notional/Contract Amount		326,125	346,842
Not Designated as Hedging Instrument [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	[1]	7,319	8,152
Not Designated as Hedging Instrument [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Fair Value	[2]	6,770	7,959
Not Designated as Hedging Instrument [Member] | Interest rate swaps [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional/Contract Amount		303,500	309,936
Liability Derivatives, Notional/Contract Amount		303,500	309,936
Not Designated as Hedging Instrument [Member] | Interest rate swaps [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	[1]	6,655	7,670
Not Designated as Hedging Instrument [Member] | Interest rate swaps [Member] | Loans Receivable [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value		216	822
Not Designated as Hedging Instrument [Member] | Interest rate swaps [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Fair Value	[2]	6,655	7,670
Not Designated as Hedging Instrument [Member] | Mortgage loan commitments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional/Contract Amount		46,351	42,296
Liability Derivatives, Notional/Contract Amount		22,625	27,191
Not Designated as Hedging Instrument [Member] | Mortgage loan commitments [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	[1]	265	30
Not Designated as Hedging Instrument [Member] | Mortgage loan commitments [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Fair Value	[2]	115	174
Not Designated as Hedging Instrument [Member] | Forward sales contracts [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Notional/Contract Amount		140,348	71,192
Liability Derivatives, Notional/Contract Amount		0	9,715
Not Designated as Hedging Instrument [Member] | Forward sales contracts [Member] | Other assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	[1]	399	452
Not Designated as Hedging Instrument [Member] | Forward sales contracts [Member] | Other liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Fair Value	[2]	$ 0	$ 115

[1] Included in Other assets on the Consolidated Statements of Financial Condition, with the exception of certain interest swaps and mortgage loan commitments (with a fair value of $216,000 at September 30, 2017 and $822,000 at December 31, 2016), which are included in Loans receivable.

[2] Included in Other liabilities on the Consolidated Statements of Financial Condition.