Acquisitions - Pending Acquisitions Narrative (Details) ZAR in Millions, $ in Millions			1 Months Ended	4 Months Ended	6 Months Ended	20 Months Ended
	Jan. 31, 2017 USD ($)	Jan. 31, 2017 ZAR	Apr. 30, 2015 power_plant MW shares	Dec. 22, 2016 USD ($)	Jun. 30, 2016 USD ($) shares	Mar. 31, 2017 USD ($)	Mar. 31, 2017 ZAR	Mar. 31, 2016 USD ($)	Feb. 24, 2016 power_plant MW	Aug. 31, 2015 USD ($) power_plant	Aug. 04, 2015 MW
BioTherm
Business Acquisition [Line Items]
Number of projects acquired | power_plant			3
Escrow deposit | $					$ 43.9					$ 65.6
NPS Star
Business Acquisition [Line Items]
Number of projects acquired | power_plant									3
Capacity of acquired power plants | MW									17.8
WXA
Business Acquisition [Line Items]
Number of projects acquired | power_plant									3
Capacity of acquired power plants | MW									17.8
Non-current restricted cash | BioTherm
Business Acquisition [Line Items]
Cash deposits held for acquisitions | $								$ 20.3
SunEdison | Del Litoral
Business Acquisition [Line Items]
Capacity of acquired power plants | MW											17.4
SunEdison | El Naranjal
Business Acquisition [Line Items]
Capacity of acquired power plants | MW											57.4
SunEdison | Bora Bora
Business Acquisition [Line Items]
Capacity of acquired power plants | MW											24.1
Scenario, forecast | BioTherm
Business Acquisition [Line Items]
Payments to acquire businesses | $	$ 8.9					$ 74.5
Scenario, forecast | Minority Interests in South African Acquisition [Member] | BioTherm
Business Acquisition [Line Items]
Payments to acquire businesses	5.9	ZAR 88.9
Scenario, forecast | USD | BioTherm
Business Acquisition [Line Items]
Payments to acquire businesses | $						67.6
Scenario, forecast | USD | BioTherm | BioTherm
Business Acquisition [Line Items]
Payments to acquire businesses | $	2.0
Scenario, forecast | ZAR | BioTherm
Business Acquisition [Line Items]
Payments to acquire businesses						$ 6.7	ZAR 100.4
Scenario, forecast | ZAR | BioTherm | BioTherm
Business Acquisition [Line Items]
Payments to acquire businesses	$ 0.8	ZAR 11.6
Common Stock | Deposits for acquisitions | BioTherm
Business Acquisition [Line Items]
Common stock issued in acquisition (in shares) | shares			544,055		544,055
Assets associated with third party sale | Subsequent event
Business Acquisition [Line Items]
Proceeds from Third Party Sale Transaction | $				$ 6.7
South Africa | BioTherm
Business Acquisition [Line Items]
Number of projects acquired | power_plant			3							3
Capacity of acquired power plants | MW			32.6