Debt and Borrowings (Narrative) (Details) £ in Thousands, $ in Thousands	12 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2013 USD ($)	Jun. 30, 2015 GBP (£)	Jun. 30, 2015 USD ($)
Debt Disclosure [Abstract]
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%
Senior notes outstanding		$ 150,000			$ 150,000
Revolving credit facility expiration date	Dec. 12, 2019
Interest coverage ratio	4.0
Leverage ratio	3.5
Consolidated leverage ratio	4.0
Line Of Credit Potential Incremental Borrowing Capacity Post-Amendment					350,000
Interest Paid	$ 22,865	20,560	$ 19,154
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Borrowings outstanding under credit agreement		614,502			660,216
Revolving credit facility					$ 1,000,000
Long-term Debt, Weighted Average Interest Rate				1.69%	1.69%
Tilda borrowing arrangement [Member]
Line of Credit Facility [Line Items]
Borrowings outstanding under credit agreement		$ 65,975			$ 29,600
Revolving credit facility | £				£ 50,393
Short-term Debt, Weighted Average Interest Rate				2.80%	2.80%
Minimum [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.20%
Minimum [Member] | Eurocurrency Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.875%
Minimum [Member] | Base Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.00%
Maximum [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.30%
Maximum [Member] | Eurocurrency Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.70%
Maximum [Member] | Base Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.70%