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Stock-Based Compensation (Details) - USD ($) | 1 Months Ended | 12 Months Ended
--- | --- | ---
May. 31, 2015 | Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Expense recognized in connection with the issuance of Deferred Stock Units (in US dollars) |  | $ 600,000 | $ 394,000 | $ 394,000
Deferred Stock Units [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Shares available for future grant under the plan |  | 887,859 |  |
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Outstanding Number |  | 6,881 |  |
Share Based Compensation Arrangement By Share Based Payment Award Non Option Equity Instruments Granted Per Director (in shares) | 176 |  |  |
Expense recognized in connection with the issuance of Deferred Stock Units (in US dollars) | $ 450,000 |  |  |
Expense per grant recognized in connection with the issuance of Deferred Stock Units (in US dollars) | $ 56,250 |  |  |
Deferred Stock Units [Member] | Newly Appointed Director [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |
Share Based Compensation Arrangement By Share Based Payment Award Non Option Equity Instruments Granted Per Director (in shares) | 468 |  |  |
Expense recognized in connection with the issuance of Deferred Stock Units (in US dollars) | $ 150,000 |  |  |

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