VARIABLE INTEREST ENTITIES - Summary of Unconsolidated VIEs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Variable Interest Entity [Line Items]
Funded commitments	$ 41,600		$ 41,572	$ 0
Aggregate funding commitment	100,000		100,000
Loss on investments in alternative energy partnerships, net	17,660	$ 0	17,660	$ 0
Tax credit			19,400
Alternative investments unfunded investment commitments	58,400		58,400
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Loss on investments in alternative energy partnerships, net	17,700
Tax credit	19,400
Equipment, net of depreciation	104,726		104,726
Other assets	43		43
Total unconsolidated assets	104,769		104,769
Total unconsolidated liabilities	0		0
Maximum loss exposure	82,340		82,340
Variable Interest Entity, Not Primary Beneficiary | Other Assets
Variable Interest Entity [Line Items]
Total unconsolidated assets	$ 23,900		$ 23,900