EQUITY AND EARNINGS PER SHARE - Schedule of Preferred Shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands			1 Months Ended			3 Months Ended
	Mar. 24, 2021	Feb. 14, 2020	Feb. 29, 2020	Aug. 31, 2019	Jul. 31, 2019	Mar. 31, 2021	Mar. 31, 2020
Class of Stock [Line Items]
Number of shares issued (in shares)						33,610	33,610
Liquidation preference						$ 840,250
Carrying Value						$ 812,992
Dividends (in dollars per share)						$ 1.32	$ 1.32
Liquidation preference per share (in dollars per share)							$ 25.00
7.50% Series A Preferred Stock
Class of Stock [Line Items]
Number of shares issued (in shares)						6,210	6,210
Liquidation preference						$ 155,250
Issuance Discount						3.15%
Carrying Value						$ 150,026
Dividends (in dollars per share)	$ 0.47					$ 0.47	$ 0.47
Interest rate					7.50%
7.125% Series B Preferred Stock
Class of Stock [Line Items]
Number of shares issued (in shares)						11,300	11,300
Liquidation preference						$ 282,500
Issuance Discount						3.15%
Carrying Value						$ 273,418
Dividends (in dollars per share)	0.45					$ 0.45	$ 0.45
Interest rate				7.125%
6.375% Series C Preferred Stock
Class of Stock [Line Items]
Number of shares issued (in shares)		16,100				16,100	16,100
Liquidation preference						$ 402,500
Issuance Discount						3.15%
Carrying Value						$ 389,548
Dividends (in dollars per share)	$ 0.40					$ 0.40	$ 0.40
Interest rate		6.375%	6.375%
Liquidation preference per share (in dollars per share)		$ 25.00