CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Tax of actuarial loss	$ 12	$ 12	$ 94	$ 62
Tax of prior service credits	$ 0	$ 0	$ 1	$ 1

Other Comprehensive Income Change In Net Actuarial Gain Loss Tax

No definition available.

Name:	wy_ChangesInUnamortizedNetPensionAndOtherPostretirementBenefitLossTaxExpenseBenefit
Namespace Prefix:	wy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration