Stock-Based Compensation Expense, by Type of Awards (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 110	$ 319	$ 409	$ 413	[1]
Employee Stock Option [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	110	127	303	221	[1]
Stock Grants [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense		$ 192	$ 106	$ 192	[1]

[1] As recast to reflect the activity of SGT beginning January 1, 2011 combined with the balances of Solar Power, Inc. beginning March 31, 2011, as required under the accounting guidelines for a transfer of an entity under common control (refer to Note 4-Acquisition of Solar Green Technology).