Inventories (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
PLUM CREEK TIMBER CO INC [Member]
Raw Materials (primarily logs)	$ 4	$ 12
Work-In-Process	1	1
Finished Goods	27	24
Total before Supplies	32	37
Supplies	11	12
Total	43	49
PLUM CREEK TIMBERLANDS L P [Member]
Raw Materials (primarily logs)	4	12
Work-In-Process	1	1
Finished Goods	27	24
Total before Supplies	32	37
Supplies	11	12
Total	$ 43	$ 49