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Employee Retirement Plans (Details) (USD $)
In Millions, except Share data, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2011
Jun. 30, 2010
Jun. 30, 2011
Jun. 30, 2010
Employee Retirement Plans (Textuals)        
Closing price per share of contributed shares to the USG corporation Retirement plan Trust $ 14.84   $ 14.84  
Discounted value shares valued for purposes of crediting the contribution to trust $ 14.39   $ 14.39  
Discount rate used to valued shares for purposes of crediting the contribution to the Trust 3.00%   3.00%  
Rate at which shares valued for purposes of crediting the contribution to trust $ 14.84   $ 14.84  
Pension [Member]
       
Components of net pension and postretirement benefits costs        
Service cost of benefits earned $ 7 $ 6 $ 14 $ 13
Interest cost on projected benefit obligation 16 16 32 32
Expected return on plan assets (17) (16) (33) (33)
Net amortization 7 4 13 8
Net cost 13 9 26 20
Employee Retirement Plans (Textuals)        
Contribution by employer 30.9      
Contribution by employer in common stock       2,084,781
Aggregate Contribution by employer     30.0  
Postretirement [Member]
       
Components of net pension and postretirement benefits costs        
Service cost of benefits earned 1 2 3 4
Interest cost on projected benefit obligation 3 5 7 9
Net amortization (5) (5) (11) (9)
Net cost (1) 2 (1) 4
United States Postretirement Benefit Plans of US Entity, Defined Benefit [Member]
       
Employee Retirement Plans (Textuals)        
Contribution by employer 10.0      
Foreign Postretirement Benefit Plans, Defined Benefit [Member]
       
Employee Retirement Plans (Textuals)        
Contribution by employer     $ 10.0