MERGER WITH PLUM CREEK (Tables)

12 Months Ended

Dec. 31, 2017

Business Combinations [Abstract]

Summarized Unaudited Pro Forma Information that Presents Combined Amounts as if this Merger Occurred at the Beginning of 2015 [Table Text Block]

Summarized Unaudited Pro Forma Information that Presents Combined Amounts as if this Merger Occurred at the Beginning of 2015

DOLLAR AMOUNTS IN MILLIONS, EXCEPT PER-SHARE FIGURES
	2016		2015
Net sales	$	6,525	$	6,664
Net earnings from continuing operations attributable to Weyerhaeuser common shareholders	$	519	$	487
Net earnings from continuing operations per share attributable to Weyerhaeuser common shareholders, basic	$	0.69	$	0.61
Net earnings from continuing operations per share attributable to Weyerhaeuser common shareholders, diluted	$	0.68	$	0.61

Initial and Final Estimated Fair Value of Identifiable Assets Acquired and Liabilities Assumed as of the Merger Date [Table Text Block]

Initial and Final Estimated Fair Value of Identifiable Assets Acquired and Liabilities Assumed as of the Merger Date

DOLLAR AMOUNTS IN MILLIONS
	PRELIMINARY ALLOCATION		MEASUREMENT PERIOD ADJUSTMENTS			FINAL ALLOCATION
Current assets	$	128	$	10		$	138
Timber and timberlands	8,124		2			8,126
Minerals and mineral rights	312		6			318
Property and equipment	272		5			277
Equity investment in Timberland Venture	876		(29		)	847
Equity investment in Real Estate Development Ventures	88		(3		)	85
Other assets	163		4			167
Total assets acquired	9,963		(5		)	9,958
Current liabilities	610		—			610
Long-term debt	2,056		—			2,056
Note payable to Timberland Venture	837		1			838
Other liabilities	77		(6		)	71
Total liabilities assumed	3,580		(5		)	3,575
Net assets acquired	$	6,383	$	—		$	6,383