Financial Assets and Liabilities - Summary of Cash and Cash Equivalents (Parenthetical) (Details) - USD ($) $ in Millions	Jun. 30, 2018	Jun. 30, 2017
Disclosure Of Financial Assets And Liabilities [Abstract]
Interest-bearing deposits at call held as security	$ 0.4	$ 0.5

Disclosure of financial assets and liabilities abstract.

No definition available.

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