Earnings Per Share (Schedule of Basic and Diluted Earnings Per Share) (Details) (USD $) In Millions, except Per Share data	3 Months Ended			6 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Income from Continuing Operations				$ 82	$ 111
Gain on Sale of Properties, net of tax				0	11
Net Income Available to Common Stockholders	44		35	82	122
Denominator for Basic Earnings per Share	162.0		162.3	161.9	162.6
Effect of Dilutive Securities - Stock Options	0.3		0.2	0.3	0.2
Effect of Dilutive Securities - Restricted Stock, Restricted Stock Units, Dividend Equivalents and Value Management Plan	0		0	0	0
Denominator for Diluted Earnings per Share - Adjusted for Dilutive Securities	162.3		162.5	162.2	162.8
Income from Continuing Operations - Basic				$ 0.51	$ 0.68
Gain on Sale of Properties, net of tax - Basic				$ 0.00	$ 0.07
Net Income - Basic	$ 0.27		$ 0.21	$ 0.51	$ 0.75
Income from Continuing Operations - Diluted				$ 0.50	$ 0.68
Gain on Sale of Properties, net of tax - Diluted				$ 0.00	$ 0.07
Net Income - Diluted	$ 0.27		$ 0.21	$ 0.50	$ 0.75
PLUM CREEK TIMBER CO INC [Member]
Income from Continuing Operations				82	111
Gain on Sale of Properties, net of tax				0	11
Net Income Available to Common Stockholders	$ 44	$ 38	$ 35	$ 82	$ 122
Denominator for Basic Earnings per Share	162.0		162.3	161.9	162.6
Denominator for Diluted Earnings per Share - Adjusted for Dilutive Securities	162.3		162.5	162.2	162.8
Income from Continuing Operations - Basic				$ 0.51	$ 0.68
Net Income - Basic	$ 0.27		$ 0.21	$ 0.51	$ 0.75
Income from Continuing Operations - Diluted				$ 0.50	$ 0.68
Net Income - Diluted	$ 0.27		$ 0.21	$ 0.50	$ 0.75