DERIVATIVES (Details 4) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Derivative [Line Items]
Fair value of derivative assets	$ 6,470,000	$ 8,733,000
Fair value of derivative liabilities	135,938,000	78,779,000
Credit Risk-Related Contingent Feature
Additional collateral required if credit rating is downgraded below investment grade	0	0
Derivatives not designated as hedging instruments
Derivative [Line Items]
Derivative assets	138,416,000	77,469,000
Derivative liabilities	136,627,000	76,679,000
Notional Amount	7,452,056,000	7,190,926,000
Derivatives not designated as hedging instruments | Interest rate swaps and options
Derivative [Line Items]
Notional amount of derivative assets	3,340,000,000	3,250,000,000
Notional amount of derivative liabilities	3,340,000,000	3,250,000,000
Derivative assets	129,599,000	67,215,000
Derivative liabilities	130,420,000	67,325,000
Notional Amount	6,685,066,000	6,494,900,000
Derivatives not designated as hedging instruments | Short-term foreign exchange contracts
Derivative [Line Items]
Derivative assets	8,800,000	10,300,000
Derivative liabilities	6,200,000	9,400,000
Notional Amount	724,900,000	653,000,000
Derivatives not designated as hedging instruments | Credit risk participation agreements (“RPAs”)
Derivative [Line Items]
Derivative assets	0	0
Derivative liabilities	11,000	4,000
Notional Amount	42,096,000	43,033,000
Interest rate derivative exposure	$ 573,000	$ 257,000
Weighted average remaining maturity	3 years	3 years 2 months
Derivatives not designated as hedging instruments | Credit risk participation agreements (“RPAs”) | Long
Derivative [Line Items]
Notional Amount	$ 33,500,000	$ 33,700,000
Derivatives not designated as hedging instruments | Credit risk participation agreements (“RPAs”) | Short
Derivative [Line Items]
Notional Amount	$ 8,600,000	$ 9,300,000
Derivatives not designated as hedging instruments | Foreign exchange options
Derivative [Line Items]
Notional Amount			$ 50,000,000
Term of contract	5 years
Fair value of derivative assets			3,700,000
Derivatives not designated as hedging instruments | Embedded derivative liabilities
Derivative [Line Items]
Notional Amount			47,800,000
Fair value of derivative liabilities			$ 3,400,000