INDEMNIFICATIONS AND GUARANTEES (Details)	9 Months Ended
	Sep. 30, 2019 USD ($) transaction loan institution	Dec. 31, 2018 USD ($) loan
Guarantor Obligations [Line Items]
Number of unrelated financial institutions | institution	5
Derivative transaction held for guarantee | loan	158	136
Notional	$ 525,711,000	$ 167,933,000
Aggregate fair value of swaps to customers, liability	(33,700,000)	(300,000)
Reserves for swap guarantees	$ 0
Minimum
Guarantor Obligations [Line Items]
Notional amount maturity period	1 year
Maximum
Guarantor Obligations [Line Items]
Notional amount maturity period	15 years
Secondary Market Loan Sales
Guarantor Obligations [Line Items]
Provision for losses at the time of sale	$ 0
Number of loans repurchased | transaction	1
Loans repurchased	$ 200,000
Interest Rate Swap
Guarantor Obligations [Line Items]
Derivative transaction held for guarantee | loan	147
Notional	$ 769,400,000	$ 581,500,000
Aggregate fair value of swaps to customers, liability	$ (34,700,000)