FAIR VALUE MEASUREMENTS - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) security	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Jan. 01, 2020 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of trading securities in the portfolio | security			1
Accounting standards update					us-gaap:AccountingStandardsUpdate201613Member
Retained earnings write-down	$ 242,175		$ 242,175		$ (361,082)
Continuing Operations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments for origination of mortgage loans held-for-sale	70,600	$ 22,600	149,500	$ 51,500
Proceeds from sale and collection of loans held-for-sale	74,100	$ 25,100	141,300	$ 48,600
Continuing Operations | Loans Held for Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) in fair value of loans held for sale included in earnings	6		284
Discontinued Operations | Loans Held for Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gains (losses) in fair value of loans held for sale included in earnings	$ (900)		$ (3,100)
Cumulative Effect, Period of Adoption, Adjustment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Retained earnings write-down					$ 24,380
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13 | Loans Held for Investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Retained earnings write-down						$ 11,200