Related Party Transactions - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2014	Dec. 31, 2013
Related Party Transaction [Line Items]
Gain from sale of investment	$ 438
Real Goods Solar \| Class A Common Stock
Related Party Transaction [Line Items]
Gain from sale of investment		$ 25,000
Common stock , Voting percentage	20.00%

Amount of gain (loss) on sale or disposal of an equity method investment.

No definition available.

Name:	us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration