| Investment Funds And Other Variable Interest Entities - Additional Information (Details) $ in Thousands | 3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
| Sep. 30, 2020  USD ($)  fund | Sep. 30, 2019  USD ($) | Sep. 30, 2020  USD ($)  fund | Sep. 30, 2019  USD ($) | Dec. 31, 2019  USD ($) | |
| Organization, Consolidation and Presentation of Financial Statements [Abstract] | |||||
| Number of investment funds | fund | 5 | 5 | |||
| Net asset position of equity method joint ventures | $ 1,370 | $ 1,370 | $ 1,292 | ||
| Expense recognized from equity method joint ventures | $ 50 | $ 73 | $ 127 | $ 147 | |
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- Definition Equity Method Investments Venture Investments, Investment Position, Net Asset (Liability) No definition available. 
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- Definition Investment Funds, Purchase Of Solar Energy Systems No definition available. 
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- Definition Amount of income (loss) for proportionate share of equity method investee's income (loss). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- References No definition available. 
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