Credit Facilities (Details) - Senior Notes	Jun. 30, 2019 AUD ($)	May 31, 2019 EUR (€)
Debt Instrument [Line Items]
Debt instrument, face amount	$ 310,000,000	€ 250,000,000
Series A Guaranteed Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount	$ 155,000,000	€ 50,000,000
Interest rate, stated percentage	3.10%	1.55%
Series B Guaranteed Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount	$ 155,000,000	€ 100,000,000
Interest rate, stated percentage	3.43%	1.74%
Series C Guaranteed Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount		€ 100,000
Interest rate, stated percentage		1.95%