CAPITAL STOCK - Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Class of Stock [Line Items]
Options exercised under incentive plans (in shares)					11,300,000
Authorized amount of stock available for repurchase			$ 1,500,000,000		$ 1,500,000,000
Shares repurchased (in shares)		4,800,000	18,300,000	27,700,000	18,300,000
Aggregate stock offering price		$ 31,300,000	$ 155,000,000.0	$ 174,700,000	$ 155,000,000.0
Preferred Stock, Par or Stated Value Per Share		$ 0.01		$ 0.01		$ 0.01
Preferred stock, redemption price (in dollars per share)		$ 25.00		$ 25.00
Preferred Stock, Shares Issued		81,900,000		81,900,000		81,900,000
Series C
Class of Stock [Line Items]
Preferred stock, redemption price (in dollars per share)			$ 25.00		$ 25.00
Preferred stock redeemed (in shares)			7,000,000.0		7,000,000.0
Preferred stock dividend rate, percentage			7.625%		7.625%
Preferred stock redeemed			$ 175,000,000.0		$ 175,000,000.0
Series H
Class of Stock [Line Items]
Preferred stock, redemption price (in dollars per share)			$ 25.00		$ 25.00
Preferred stock redeemed (in shares)					2,200,000
Preferred stock dividend rate, percentage					8.125%
Preferred stock redeemed					$ 55,000,000.0
Series I
Class of Stock [Line Items]
Preferred stock redeemed (in shares)					17,700,000
Preferred stock dividend rate, percentage				6.75%	6.75%
Preferred stock redeemed					$ 442,500,000
Preferred Stock, Shares Issued		17,700,000		17,700,000		17,700,000
Public Offering
Class of Stock [Line Items]
Sale of stock, shares issued (in shares)					75,000,000.0
Proceeds from sale of stock					$ 730,500,000
Public Offering, Additional Share Purchase Option
Class of Stock [Line Items]
Sale of stock, shares issued (in shares)					11,300,000
Proceeds from sale of stock					$ 109,600,000
Option to purchase additional shares, period					30 days
At-the-market Sale Program
Class of Stock [Line Items]
Sale of stock, shares issued (in shares)				0	56,000,000.0
Proceeds from sale of stock					$ 569,100,000
Aggregate stock offering price	$ 1,500,000,000
Preferred Stock
Class of Stock [Line Items]
Preferred stock redeemed		$ 0	$ 169,466,000	$ 0	$ 224,466,000