SHAREHOLDERS' INTEREST - Reconciliation of Our Common Share Activity (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Outstanding at beginning of year	746,391	755,223	748,528
Repurchased	(2,349)	(11,410)	0
Outstanding at end of year	745,300	746,391	755,223
Stock options
Class Of Stock [Line Items]
Stock issued under share-based payment arrangement	660	2,026	5,970
Vested restricted stock units
Class Of Stock [Line Items]
Stock issued under share-based payment arrangement	480	466	605
Vested performance share units
Class Of Stock [Line Items]
Stock issued under share-based payment arrangement	118	86	120