Stock-based Compensation - Additional Information (Detail)	3 Months Ended			9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011		Sep. 30, 2012	Sep. 30, 2011		Jun. 08, 2012	Dec. 31, 2011	Jul. 22, 2011	Jun. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-vesting forfeiture rate	20.70%	26.30%
Performance-based options outstanding							400,000	5,171,500	400,000	525,868	[1]
Dividend yield	0.00%	0.00%	[1]	0.00%	0.00%	[1]
Percentage of total outstanding shares reserved and available for grant and issuance pursuant to Equity Incentive Plan				9.00%
Maximum limit of stock granted for incentive stock options	2,000,000			2,000,000
Shares available to issue under Equity Incentive Plan	11,081,198			11,081,198
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant and vesting periods				4 years
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant and vesting periods				3 years
Time Based Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Time-based options increment rate				25.00%
Time-based options expiration period				5 years
Performance based option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance-based options outstanding	0			0				0
Time-based and performance-based options life				5 years

[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).