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Fair Value of Financial Instruments (Narrative) (Details) - USD ($) $ in Thousands | Mar. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Liabilities | $ 1,690 | $ 785
Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Liabilities | 1,405 | 765
Level 2 [Member] | Secured Notes One [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Secured notes | 0 | 120,000
Level 2 [Member] | Secured Notes Two [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Secured notes | 0 | 20,000
Borrowings [Member] | Unsecured debt [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Liabilities | 374,633 | 180,000
Borrowings [Member] | Unsecured debt [Member] | Level 2 [Member] |  |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |  |
Liabilities | $ 374,633 | $ 180,000

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