SHAREHOLDERS' INTEREST - Reconciliation of Our Common Share Activity (Details) - shares		12 Months Ended
	Jul. 01, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Outstanding at beginning of year		748,528,131	510,483,000	524,474,000
Preference shares converted to common shares	23,200,000	0	23,345,000	0
Repurchased		0	(67,817,000)	(16,190,000)
Outstanding at end of year		755,222,727	748,528,131	510,483,000
Stock options
Class of Stock [Line Items]
Shares issued for share-based compensation		5,970,000	2,571,000	1,592,000
Restricted stock units
Class of Stock [Line Items]
Shares issued for share-based compensation		605,000	840,000	365,000
Performance share units
Class of Stock [Line Items]
Shares issued for share-based compensation		120,000	219,000	242,000
Plum Creek
Class of Stock [Line Items]
Issuance from merger with Plum Creek (Note 4)		0	278,887,000	0