Summary of Significant Accounting Policies - Estimated Useful Lives of the Respective Assets (Details)	12 Months Ended
Dec. 31, 2016
Accounting Policies [Abstract]
System equipment costs, Useful Lives	30 years
Initial direct costs related to solar energy systems, Useful Lives	20 years

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration