REAL ESTATE - Investments (Details) $ in Thousands, ft² in Millions	Sep. 30, 2020 USD ($) ft² property	Jan. 31, 2020 property
Real Estate Properties [Line Items]
Rentable square feet | ft²	2.5
Percentage of real estate occupied	74.00%
Real estate | $	$ 767,850
Office Properties
Real Estate Properties [Line Items]
Number of real estate properties	4
Office Campus
Real Estate Properties [Line Items]
Number of real estate properties	1	1
Office Buildings, Campus
Real Estate Properties [Line Items]
Number of real estate properties	2