Note 3 - Summary of Significant Accounting Policies (Detail) (USD $)	12 Months Ended							3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2012 Solar Modules [Member]	Dec. 31, 2012 Inverter and Balance of System Components [Member]	Dec. 31, 2012 Minimum [Member]	Dec. 31, 2012 Maximum [Member]	Dec. 31, 2012 Greek Projects [Member]	Dec. 31, 2012 Greek Projects [Member]	Dec. 31, 2012 Italy Project [Member]
Proceeds from Customers for Progress Payments (in Dollars)	$ 10,800,000	$ 33,000,000
Loss on Contracts (in Dollars)	2,729,000							2,700,000
Construction in Progress, Gross (in Dollars)	16,078,000		[1]					14,700,000	14,700,000	1,400,000
Revenues (in Dollars)									0	0
Contract Terms						30 days	365 days
Shipping, Handling and Transportation Costs (in Dollars)	600,000	1,000,000
Advertising Expense (in Dollars)	100,000	200,000
Warranty Term				25 years	5 years
Pension Expense (in Dollars)	$ 600,000	$ 400,000

[1] As recast to reflect the balances of Solar Green Technology S.p.A. ("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 5 -Acquisition of Solar Green Technology).