Fair Value of Financial Instruments - Hybrid Liability (Details) $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($)
Investments in time and call deposits
Current period additions	$ 12.9
Balance at December 31, 2018	$ 12.9

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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