Income Taxes (Narrative) (Details) - Australian Taxation Office [Member]	3 Months Ended
Sep. 30, 2017
Minimum [Member]
Income Taxes [Line Items]
Tax year under audit	2009
Maximum [Member]
Income Taxes [Line Items]
Tax year under audit	2013

Tax year being audited in the income tax examination, in CCYY format.

No definition available.

Name:	us-gaap_IncomeTaxExaminationYearUnderExamination
Namespace Prefix:	us-gaap_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration