COMMITMENTS AND CONTINGENCIES - Allowance for Unfunded Commitments (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Provision for unfunded commitments	$ (3,984)	$ 26,692	$ (21,462)	$ 132,188
Unfunded Loan Commitments
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	22,314	37,503	32,854	1,077
Provision for unfunded commitments	(5,516)	(10,131)	(16,056)	13,581
Ending balance, Allowance	16,798	27,372	16,798	27,372
Unfunded Loan Commitments \| Adjustment
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance, Allowance	$ 0	$ 0	$ 0	$ 12,714

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant