Business Acquisitions Business Acquisitions - November 2015 Drop Down (Details)		Feb. 19, 2016 USD ($)	Nov. 03, 2015 USD ($)	Sep. 30, 2016 MW	Nov. 02, 2015 USD ($) MW
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]			4,686
November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired					75.00%
Number of Facilities					12
Payments to Acquire Businesses, Gross		$ 207,000,000	$ 209,000,000
Business Combination, Long-term Debt			193,000,000
Business Acquisition, Consideration Transferred, Working Capital		$ 2,000,000
Financial Institutions [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value			$ 159,000,000
Taxable Income Allocation, Pre-Flip			99.00%
Taxable Income Allocation, Post-Flip			8.53%
Post-Flip Point [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Percentage of Cash Available for Distributions			68.60%
Pre-Flip Point [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Percentage of Cash Available for Distributions			75.00%
Pre-determined Date Through Flip Point If Flip Has Not Occured [Member] | Financial Institutions [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Percentage of Cash Available for Distributions			100.00%
Wind Farms [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]			1,999
Wind Farms [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1]				814

[1] Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of September 30, 2016.