INVESTMENTS - Ownership Carrying Values (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Jun. 15, 2022	Dec. 31, 2021	Nov. 30, 2021	Jul. 31, 2020	Dec. 31, 2019	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Investments	$ 73,589		$ 54,408
Intermodal Finance I, Ltd.
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	51.00%						51.00%
Investments	$ 0		0
Long Ridge Energy & Power LLC
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%					50.10%
Investments	$ 0		0			$ 155,600
Long Ridge Energy & Power LLC | Other Liabilities
Schedule of Equity Method Investments [Line Items]
Investments	$ 187,200		$ 17,500
FYX Trust HoldCo LLC
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	66.00%		14.00%		14.00%
Investments	$ 0		$ 1,255		$ 1,300
GM-FTAI Holdco LLC
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		27.00%
Investments	$ 68,025		52,295
Clean Planet Energy USA LLC
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%			50.00%
Investments	$ 5,564		$ 858	$ 1,000