Fair Value Measurement - Schedule of Fair Value Measurement of Debt Instrument (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	$ 754,686	$ 534,764
Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	764,521	541,707
Lines of Credit | Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	374,300	197,000
Lines of Credit | Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	374,300	197,000
Syndicated Term Loans | Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	189,730	169,344
Syndicated Term Loans | Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	189,730	169,344
Bank Term Loan | Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	51,932	30,739
Bank Term Loan | Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	52,079	32,692
Notes Payable | Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	34,819	32,781
Notes Payable | Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	34,682	32,568
Solar Asset-Backed Notes | Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	103,905	104,900
Solar Asset-Backed Notes | Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	$ 113,730	$ 110,103