Income Taxes (Schedule of Income Before Income Tax, Domestic and Foreign) (Detail) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2017	[1]	Sep. 30, 2017	[1]	Jun. 30, 2017	[1]	Mar. 31, 2017	[1]	Dec. 31, 2016	[2]	Sep. 30, 2016	[2]	Jun. 30, 2016	[2]	Mar. 31, 2016	[2]	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S.																	$ 297		$ 411		$ 1,013
Non-U.S.																	551		384		119
EARNINGS (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES AND EQUITY EARNINGS (LOSSES)	$ 197		$ 457		$ (23)		$ 217		$ 244		$ 320		$ (76)		$ 307		$ 848	[1]	$ 795	[2]	$ 1,132

[1] Includes the following pre-tax charges (gains): 2017In millions Q1 Q2 Q3 Q4Gain on sale of investment in ArborGen $— $(14) $— $—Costs associated with the pulp business acquired in 2016 4 5 6 18Amortization of Weyerhaeuser inventory fair value step-up 14 — — —Holmen bargain purchase gain (6) — — —Abandoned property removal 2 5 7 6Kleen Products settlement — 354 — —Asia Foodservice sale — 9 — —Brazil Packaging wood supply accelerated amortization — — 10 —Debt extinguishment costs — — — 83Interest income on income tax refund claims — (4) — (1)Other items — (2) — —Non-operating pension expense 31 34 33 386Total $45 $387 $56 $492

[2] Includes the following pre-tax charges (gains): 2016In millions Q1 Q2 Q3 Q4Riegelwood mill conversion costs $9 $— $— $—India Packaging evaluation write-off — — 17 —Early debt extinguishment costs — — 29 —Write-off of certain regulatory pre-engineering costs — — 8 —Costs associated with the newly acquired pulp business — 5 7 19Asia Box impairment / restructuring 37 28 5 —Gain on sale of investment in Arizona Chemical (8) — — —Turkey mill closure — — — 7Amortization of Weyerhaeuser inventory fair value step-up — — — 19Non-operating pension expense 44 487 42 37Total $82 $520 $108 $82