Document and Entity Information	6 Months Ended
	Jun. 30, 2011	Jul. 25, 2011
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2011
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q2
Entity Registrant Name	PLUM CREEK TIMBER CO INC
Entity Central Index Key	0000849213
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		161,985,207
PLUM CREEK TIMBERLANDS L P [Member]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2011
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q2
Entity Registrant Name	Plum Creek Timberlands LP
Entity Central Index Key	0001296350
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer