Organization - Additional Information (Detail) - USD ($) $ in Thousands	Jul. 27, 2017	Jun. 30, 2017	Dec. 31, 2016
Schedule Of Description Of Business [Line Items]
Equity Method Investments		$ 240,561	$ 233,294
Pattern Development [Member]
Schedule Of Description Of Business [Line Items]
Ownership Interest in the Company by Pattern Development		9.00%
Hatchet Ridge [Member]
Schedule Of Description Of Business [Line Items]
Ownership Percentage		100.00%
St Josephs [Member]
Schedule Of Description Of Business [Line Items]
Ownership Percentage		100.00%
Spring Valley [Member]
Schedule Of Description Of Business [Line Items]
Ownership Percentage		100.00%
Pattern Santa Isabel LLC [Member]
Schedule Of Description Of Business [Line Items]
Ownership Percentage		100.00%
Ocotillo [Member]
Schedule Of Description Of Business [Line Items]
Ownership Percentage		100.00%
Pattern Gulf Wind LLC [Member]
Schedule Of Description Of Business [Line Items]
Ownership Percentage		100.00%
Lost Creek Wind, LLC [Member]
Schedule Of Description Of Business [Line Items]
Ownership Percentage		100.00%
Subsequent Event [Member] | Pattern Development 2.0 [Member]
Schedule Of Description Of Business [Line Items]
Equity Method Investments	$ 60,000
Percentage of ownership	20.00%