Income Taxes	6 Months Ended
Dec. 31, 2017
Income Taxes [Abstract]
Income Taxes	(7) Income Taxes In accordance with ASC 740 Income Taxes, each interim reporting period is considered integral to the annual period, and tax expense is measured using an estimated annual effective tax rate. An entity is required to record income tax expense each quarter based on its annual effective tax rate estimated for the full fiscal year and use that rate to provide for income taxes on a current year-to-date basis, adjusted for discrete taxable events that occur during the interim period. Our income tax returns are based on calculations and assumptions subject to audit by various tax authorities. In addition, the calculation of our tax liabilities involves dealing with uncertainties in the application of complex tax laws. We regularly assess the potential outcomes of examinations by tax authorities in determining the adequacy of our provision for income taxes. Any final assessment resulting from tax audits may result in material changes to our past or future taxable income, tax payable or deferred tax assets, and may require us to pay penalties and interest that could materially adversely affect our financial results. We are currently under audit by the Australian Taxation Office (“ATO”) for the tax years 2009 to 2013. In December 2017, we received a Statement of Audit Position from the ATO which provides the ATO auditor’s position on the factual and technical issues under audit, and included proposed adjustments totaling approximately $150.0 million in additional tax. The audit is ongoing and we have not received a Notice of Amended Assessment. We do not agree with the ATO’s position and continue to believe we are more likely than not to be successful in defending our position, and therefore have not recognized any additional tax liabilities in relation to this audit. We will pursue all administrative and legal steps in defense of our position; however, if we are not successful in defending our position, the outcome may materially adversely affect our financial results. Our income tax expense, short-term income taxes payable and long-term income taxes payable were impacted by charges associated with the Tax Cuts and Jobs Act (“U.S. legislation”) enacted on December 22, 2017, which resulted in additional income tax expense of $126.6 million. Specifically, the income tax expense includes both the transition tax imposed on our accumulated foreign earnings, which resulted in additional income tax expense of $119.9 million, and the write down in the carrying value of our net deferred tax assets due to the lower corporate tax rate, which resulted in additional income tax expense of $6.7 million. On December 22, 2017, the SEC issued guidance under Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”) directing taxpayers to consider the impact of the U.S. legislation as “provisional” when it does not have the necessary information available, prepared or analyzed (including computations) in reasonable detail to complete its accounting for the change in tax law. In accordance with SAB 118, the additional estimated income tax of $126.6 million represents our best estimate based on interpretation of the U.S. legislation as we are still accumulating data to finalize the underlying calculations, or in certain cases, the U.S. Treasury is expected to issue further guidance on the application of certain provisions of the U.S. legislation. In accordance with SAB 118, the additional estimated income tax of $126.6 million is considered provisional and will be finalized before December 22, 2018.

(7) Income Taxes

In accordance with ASC 740 Income Taxes, each interim reporting period is considered integral to the annual period, and tax expense is measured using an estimated annual effective tax rate. An entity is required to record income tax expense each quarter based on its annual effective tax rate estimated for the full fiscal year and use that rate to provide for income taxes on a current year-to-date basis, adjusted for discrete taxable events that occur during the interim period.

Our income tax returns are based on calculations and assumptions subject to audit by various tax authorities. In addition, the calculation of our tax liabilities involves dealing with uncertainties in the application of complex tax laws. We regularly assess the potential outcomes of examinations by tax authorities in determining the adequacy of our provision for income taxes. Any final assessment resulting from tax audits may result in material changes to our past or future taxable income, tax payable or deferred tax assets, and may require us to pay penalties and interest that could materially adversely affect our financial results.

We are currently under audit by the Australian Taxation Office (“ATO”) for the tax years 2009 to 2013. In December 2017, we received a Statement of Audit Position from the ATO which provides the ATO auditor’s position on the factual and technical issues under audit, and included proposed adjustments totaling approximately $150.0 million in additional tax. The audit is ongoing and we have not received a Notice of Amended Assessment. We do not agree with the ATO’s position and continue to believe we are more likely than not to be successful in defending our position, and therefore have not recognized any additional tax liabilities in relation to this audit. We will pursue all administrative and legal steps in defense of our position; however, if we are not successful in defending our position, the outcome may materially adversely affect our financial results.

Our income tax expense, short-term income taxes payable and long-term income taxes payable were impacted by charges associated with the Tax Cuts and Jobs Act (“U.S. legislation”) enacted on December 22, 2017, which resulted in additional income tax expense of $126.6 million. Specifically, the income tax expense includes both the transition tax imposed on our accumulated foreign earnings, which resulted in additional income tax expense of $119.9 million, and the write down in the carrying value of our net deferred tax assets due to the lower corporate tax rate, which resulted in additional income tax expense of $6.7 million.

On December 22, 2017, the SEC issued guidance under Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act (“SAB 118”) directing taxpayers to consider the impact of the U.S. legislation as “provisional” when it does not have the necessary information available, prepared or analyzed (including computations) in reasonable detail to complete its accounting for the change in tax law. In accordance with SAB 118, the additional estimated income tax of $126.6 million represents our best estimate based on interpretation of the U.S. legislation as we are still accumulating data to finalize the underlying calculations, or in certain cases, the U.S. Treasury is expected to issue further guidance on the application of certain provisions of the U.S. legislation. In accordance with SAB 118, the additional estimated income tax of $126.6 million is considered provisional and will be finalized before December 22, 2018.