Significant Accounting Policies Insurance (Details) - Dec. 31, 2015 AUD in Millions, $ in Millions	AUD	USD ($)
Liability Policies [Member]
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Self-insured retention, maximum per incident		$ 2.5
Property policies [Member]
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Self-insured retention, maximum per incident		$ 1.0
Australia [Member] | Property policies [Member]
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Self-insured retention, maximum per incident | AUD	AUD 2.5