CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Changes in unamortized actuarial loss, tax expense (benefit)	$ 111	$ 19
Changes in unamortized net prior service credit, tax expense (benefit)	$ 0	$ 0

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