PLEDGED ASSETS - Assets Pledged By Counterparties (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Pledged Assets [Line Items]
Securities Pledged By Counterparties	$ 152,015	$ 1,418
Cash
Pledged Assets [Line Items]
Securities Pledged By Counterparties	11,650	1,418
US Treasury Securities [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	140,365	0
Repurchase Agreement [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	10,920	1,418
Repurchase Agreement [Member] | Cash
Pledged Assets [Line Items]
Securities Pledged By Counterparties	10,920	1,418
Repurchase Agreement [Member] | US Treasury Securities [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	0	0
Reverse Repurchase Agreements [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	139,843	0
Reverse Repurchase Agreements [Member] | Cash
Pledged Assets [Line Items]
Securities Pledged By Counterparties	0	0
Reverse Repurchase Agreements [Member] | US Treasury Securities [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	139,843	0
Derivative Agreements [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	1,252	0
Derivative Agreements [Member] | Cash
Pledged Assets [Line Items]
Securities Pledged By Counterparties	730	0
Derivative Agreements [Member] | US Treasury Securities [Member]
Pledged Assets [Line Items]
Securities Pledged By Counterparties	$ 522	$ 0