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Summary of Significant Accounting Policies - Deferred Costs (Textual) (Details) | 12 Months Ended
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Dec. 31, 2018
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract] |
Remaining Lease Period - Minimum | 1 year
Remaining Lease Period - Maximum | 16 years

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- Definition Remaining Lease Period - Maximum + References No definition available. + Details
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- References No definition available. + Details
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