Subsequent Events - Additional Information (Details) - Subsequent Event $ in Millions	Oct. 31, 2015 USD ($) InvestmentFund
Subsequent Event [Line Items]
Number of new investment funds	3
Maximum
Subsequent Event [Line Items]
Commitments to tax equity investors for investment of funds \| $	$ 335.0

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration