Debt and Borrowings (Narrative) (Details) € in Thousands, £ in Thousands, $ in Thousands	3 Months Ended	6 Months Ended
	Dec. 31, 2015 GBP (£)	Dec. 31, 2015 GBP (£)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 EUR (€)	Jun. 30, 2015 USD ($)
Line of Credit Facility [Line Items]
Aggregate principal amount of senior notes			$ 150,000
Senior notes term, in years		10
Senior notes maturity date		May 02, 2016
Senior notes interest percentage	5.98%	5.98%	5.98%	5.98%
Senior notes outstanding			$ 150,000		$ 150,000
Line Of Credit Potential Incremental Borrowing Capacity Post-Amendment			350,000
Revolving credit facility expiration date		Dec. 12, 2019
Interest coverage ratio		4.0
Leverage ratio	3.5
Consolidated leverage ratio		4.0
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility			1,000,000
Borrowings outstanding under credit agreement			$ 780,882		660,216
Long-term Debt, Weighted Average Interest Rate	1.77%	1.77%	1.77%	1.77%
Revolving Credit Facility [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		0.20%
Revolving Credit Facility [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		0.30%
Eurocurrency Rate [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.875%
Eurocurrency Rate [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.70%
Base Rate [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.00%
Base Rate [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.70%
Tilda borrowing arrangement [Member]
Line of Credit Facility [Line Items]
Revolving credit facility | £	£ 50,000	£ 50,000
Borrowings outstanding under credit agreement			$ 35,898		$ 29,600
Short-term Debt, Weighted Average Interest Rate	2.80%	2.80%	2.80%	2.80%
Mona [Member]
Line of Credit Facility [Line Items]
Revolving credit facility | €				€ 6,000
Short-term Debt, Weighted Average Interest Rate	2.50%	2.50%	2.50%	2.50%