EARNINGS PER COMMON SHARE (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Earnings Per Share [Abstract]
Net income	$ 30,639	$ 28,803	$ 112,682	$ 94,659	$ 161,579
Less: Net income attributable to noncontrolling interest	(7,207)	(4,115)	(12,453)	(9,968)
NET INCOME ATTRIBUTABLE TO RAYONIER INC.	$ 23,432	$ 24,688	$ 100,229	$ 84,691
Shares used for determining basic earnings per common share (in shares)	129,142,931	128,610,696	129,005,074	126,934,003
Dilutive effect of:
Stock options (in shares)	73,372	84,380	85,000	94,528
Performance and restricted shares (in shares)	539,571	270,704	584,364	315,476
Shares used for determining diluted earnings per common share (in shares)	129,755,874	128,965,780	129,674,438	127,344,007
Basic earnings per common share attributable to Rayonier Inc. (in dollars per share)	$ 0.18	$ 0.19	$ 0.78	$ 0.67
Diluted earnings per common share attributable to Rayonier Inc. (in dollars per share)	$ 0.18	$ 0.19	$ 0.77	$ 0.67