Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v2.4.0.6
Income Taxes - Additional Information (Detail) (USD $)
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Income Taxes [Line Items]    
Ownership percentage in a subsidiary 51.40%  
Change in ownership of a company limiting period 3 years  
Alternative minimum tax credit carryforwards $ 500,000  
General business tax credit carryforwards 254,000  
Foreign tax credit carryforwards 164,000  
Tax credit carryforward expiration year 2018  
Deferred tax asset related to Tax Sharing Agreement 1,600,000  
Tax write-offs recorded to additional paid-in capital as a result of the exercise of stock options   13,000
Tax benefit recognized that has a likelihood of being realized upon ultimate resolution 50.00%  
Maximum
    
Income Taxes [Line Items]    
Ownership percentage in a subsidiary 80.00%  
Minimum
    
Income Taxes [Line Items]    
Change in ownership of a company limiting the net operating loss carryforward 50.00%  
Foreign Tax Authority
    
Income Taxes [Line Items]    
Undistributed foreign earnings for which provision for U.S. federal and state income taxes made 600,000  
State and Local Jurisdiction
    
Income Taxes [Line Items]    
Tax effected net operating loss carryforwards 15,800,000  
Operating loss carryforwards, if unused, expiration year 2018  
Internal Revenue Service (IRS)
    
Income Taxes [Line Items]    
Tax effected net operating loss carryforwards 1,600,000  
Operating loss carryforwards, if unused, expiration year 2018  
Real Goods Solar
    
Income Taxes [Line Items]    
Income tax expense benefits 6,000,000 7,100,000
Credit to additional paid-in capital   600,000
Tax effected net operating loss carryforwards 4,400,000  
Deferred tax asset related to Tax Sharing Agreement 1,600,000  
Additional paid-in capital charged as a result of adjustments to a deferred tax liability   $ 900,000