Long-term Debt Schedule of Future Payments Including Capital Leases (Details) $ in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2018 AUD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 01, 2010 AUD ($)	Dec. 01, 2010 USD ($)
Debt Instrument, Redemption [Line Items]
2019		$ 36,731
2020		110,897
2021		121,360
2022		494,533
2023		1,537,084
Thereafter		215,699
Total		2,516,304
Non-interest bearing loan, carrying value		2,391,633	$ 2,256,312
Non interest bearing note [Member]
Debt Instrument, Redemption [Line Items]
Non-interest bearing loan		35,200		$ 50.0	$ 48,200
Non-interest bearing loan, maturity date	Jan. 14, 2054
Non-interest bearing loan, carrying value	$ 3.3	$ 2,400		$ 1.8	$ 1,700