Stockholders' Equity Stockholders' Equity - Summary of Noncontrolling Interest Balances By Projects (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Noncontrolling Interest [Line Items]
Noncontrolling interest	$ 1,175,430	$ 891,246	$ 916,670	$ 944,262
El Arrayan [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest	31,644	32,237
Logan's Gap [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest	174,553	180,092
Panhandle One [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest	180,510	190,415
Panhandle Two [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest	160,458	170,139
Post Rock [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest	169,407	178,676
Amazon Wind Farm Flower Ridge [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest	137,637	139,687
Broadview Project [Member]
Noncontrolling Interest [Line Items]
Noncontrolling interest	$ 321,221	$ 0