Fair Value Measurements - Fair Value of Other Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Carrying Amount
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Borrowings under Credit Facility	$ 0	$ 49,731
Fair Value
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Borrowings under Credit Facility	$ 0	$ 49,731

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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