CAPITAL STOCK - Summary of Dividend Distribution Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Dividends Payable [Line Items]
Dividends and dividend equivalents declared on common stock and share-based awards	$ 319,768	$ 309,175	$ 946,648	$ 976,966
Distributions declared per common share (in dollars per share)	$ 0.22	$ 0.22	$ 0.66	$ 0.69
Distributions paid to common stockholders after period end	$ 318,986	$ 308,644	$ 318,986	$ 308,644
Distributions paid per common share after period end (in dollars per share)	$ 0.22	$ 0.22	$ 0.22	$ 0.22
Series D
Dividends Payable [Line Items]
Preferred dividends declared	$ 0	$ 8,625	$ 0	$ 25,875
Preferred series dividends declared (in dollars per share)	$ 0	$ 0.469	$ 0	$ 1.406
Series F
Dividends Payable [Line Items]
Preferred dividends declared	$ 12,510	$ 12,510	$ 37,530	$ 37,530
Preferred series dividends declared (in dollars per share)	$ 0.434	$ 0.434	$ 1.303	$ 1.303
Series G
Dividends Payable [Line Items]
Preferred dividends declared	$ 6,906	$ 6,906	$ 20,718	$ 20,718
Preferred series dividends declared (in dollars per share)	$ 0.406	$ 0.406	$ 1.219	$ 1.219
Series I
Dividends Payable [Line Items]
Preferred dividends declared	$ 7,467	$ 7,468	$ 22,401	$ 22,404
Preferred series dividends declared (in dollars per share)	$ 0.422	$ 0.422	$ 1.266	$ 1.266