Long-Term Debt (Narrative) (Details)	Sep. 30, 2015 USD ($)	Jun. 30, 2015
Debt Covenant To Actual Ratios [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 325,000,000
Revolving credit facility present accordion provisions	$ 50,000,000
Term Number Two [Member]
Debt Covenant To Actual Ratios [Line Items]
Ratio of indebtedness to net capital (in Ratio) (below at March 31, 2015)	3.5
Ratio Minimum Per Covenant [Member]
Debt Covenant To Actual Ratios [Line Items]
Ratio of earnings to fixed cost obligations (in Ratio)	1.2
Ratio Actual [Member]
Debt Covenant To Actual Ratios [Line Items]
Ratio of indebtedness to net capital (in Ratio) (below at March 31, 2015)	2.66	2.50
Ratio of earnings to fixed cost obligations (in Ratio)	2.78
Decline in outstanding revolving credit facility	0.50%
Revolving Credit Facility [Member]
Debt Covenant To Actual Ratios [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 200,000,000
Term Loan [Member]
Debt Covenant To Actual Ratios [Line Items]
Revolving credit facility, maximum borrowing capacity	125,000,000
Credit Agreement [Member] | Revolving Credit Facility [Member]
Debt Covenant To Actual Ratios [Line Items]
Amount drawn under term loan facility	$ 63,000,000
Credit Agreement [Member] | Revolving Credit Facility [Member] | QTD [Member]
Debt Covenant To Actual Ratios [Line Items]
Weighted average interest rate	2.60%
Credit Agreement [Member] | Revolving Credit Facility [Member] | YTD [Member]
Debt Covenant To Actual Ratios [Line Items]
Weighted average interest rate	2.50%
Credit Agreement [Member] | Term Loan [Member]
Debt Covenant To Actual Ratios [Line Items]
Amount drawn under term loan facility	$ 113,300,000
Letters of credit issued and outstanding	$ 0