RECENTLY ISSUED ACCOUNTING STANDARDS - NARRATIVE (Details) - USD ($)	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	$ 657,500,000	$ 517,900,000	$ 535,700,000	$ 193,500,000
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right to use asset				72,000,000.0
Lease liability				72,000,000.0
Retained earnings				$ 0