Stockholders' Equity (Schedule Of Components Of Stockholders Equity) (Details) (USD $) In Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	$ 44		$ 35	$ 82	$ 122
PLUM CREEK TIMBER CO INC [Member] | Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance Shares	161.9	161.6		161.6
Beginning Balance	2	2		2
Stock Option Exercises (in shares)	0.1	0.2
Stock Option Exercises	0
Shares Issued under Stock Incentive Plans (shares)		0.1
Shares Issued under Stock Incentive Plans		0
Stock Repurchased During Period, Shares		0
Common Stock Repurchased		0
Ending Balance Shares	162.0	161.9		162.0
Ending Balance	2	2		2
PLUM CREEK TIMBER CO INC [Member] | Paid-in Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	2,252	2,243		2,243
Stock Option Exercises	2	7
Shares Issued under Stock Incentive Plans		0
Share-Based Compensation	2	2
Ending Balance	2,256	2,252		2,256
PLUM CREEK TIMBER CO INC [Member] | Retained Earnings (Accumulated Deficit) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	21	51		51
Net Income	44	38
Dividends	(68)	(68)
Ending Balance	(3)	21		(3)
PLUM CREEK TIMBER CO INC [Member] | Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance		(911)		(911)
Common Stock Repurchased		(1)
Ending Balance	(912)	(912)		(912)
PLUM CREEK TIMBER CO INC [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(10)	(11)		(11)
Other Comprehensive Income (Loss), net of tax	1	1
Ending Balance	(9)	(10)		(9)
PLUM CREEK TIMBER CO INC [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance Shares		161.6		161.6
Beginning Balance	1,353	1,374		1,374
Net Income	44	38	35	82	122
Other Comprehensive Income (Loss), net of tax	1	1
Total Comprehensive Income	45	39
Dividends	(68)	(68)
Stock Option Exercises	2	7
Shares Issued under Stock Incentive Plans		0
Share-Based Compensation	2	2
Common Stock Repurchased		(1)
Ending Balance Shares	162.0			162.0
Ending Balance	$ 1,334	$ 1,353		$ 1,334