Variable Interest Entities (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2011 PLUM CREEK TIMBER CO INC [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2008 PLUM CREEK TIMBER CO INC [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Jun. 30, 2011 PLUM CREEK TIMBERLANDS L P [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2008 PLUM CREEK TIMBERLANDS L P [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2008 PLUM CREEK TIMBER CO INC [Member] Affiliate Of The Campbell Group LLC [Member]	Dec. 31, 2008 PLUM CREEK TIMBERLANDS L P [Member] Affiliate Of The Campbell Group LLC [Member]	Dec. 31, 2008 PLUM CREEK TIMBERLANDS L P [Member] PC Ventures [Member]	Jun. 30, 2011 PLUM CREEK TIMBER CO INC [Member] Timberland Venture [Member]	Jun. 30, 2011 PLUM CREEK TIMBERLANDS L P [Member] Timberland Venture [Member]	Jun. 30, 2011 PLUM CREEK TIMBER CO INC [Member]	Dec. 31, 2010 PLUM CREEK TIMBER CO INC [Member]	Jun. 30, 2011 PLUM CREEK TIMBERLANDS L P [Member]	Dec. 31, 2010 PLUM CREEK TIMBERLANDS L P [Member]
Variable Interest Entity, Qualitative or Quantitative Information, Date Involvement Began	10/1/2008		10/1/2008
Contributed acres of timberlands to Southern Diversified Timber, LLC in exchange for a common and preferred interest		454,000		454,000
Preferred interest in venture		$ 705		$ 705
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage		9.00%		9.00%
Common interest in venture		78		78
Amount borrowed from the Timberland Venture		783					783			783	783
Proceeds from Partnership Contribution				783
Line of Credit Facility, Maximum Borrowing Capacity								15	15
Equity Investment in Timberland Venture										203	201	203	201
Maximum exposure to loss	203		203
Cash Contribution to VIE					783	783
Ownership Percentage of VIE					91.00%	91.00%
Total Common Interests in Venture								$ 861	$ 861