Fair Value Measurement - Schedule of Carrying Values and Fair Values of Debt Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	$ 898,023	$ 534,764
Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	897,996	541,707
Lines of Credit | Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	489,200	197,000
Lines of Credit | Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	489,200	197,000
Syndicated Term Loans | Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	189,989	169,344
Syndicated Term Loans | Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	189,989	169,344
Bank Term Loan | Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	81,307	30,739
Bank Term Loan | Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	80,542	32,692
Notes Payable | Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	36,232	32,781
Notes Payable | Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	35,396	32,568
Solar Asset-Backed Notes | Carrying Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	101,295	104,900
Solar Asset-Backed Notes | Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Debt Instrument, Fair Value	$ 102,869	$ 110,103