Long-Term Debt (Details Textual 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jun. 30, 2012
Unsecured Revolving Credit Facility [Member]
Long Term Debt (Additional Textual) [Abstract]
Description of interest rate on credit facility	Borrowings in U.S. dollars under the new credit facility, at our election, bear interest at (a) the adjusted London Interbank Offered Rate ("LIBOR") for specified interest periods plus a margin, which can range from 1.00% to 2.00%, determined with reference to our consolidated leverage ratio or (b) a floating rate equal to the greatest of (i) JPMorgan's prime rate, (ii) the federal funds rate plus 0.50% and (iii) the adjusted LIBOR for a one month interest period plus 1.00%, plus, in each case, a margin determined with reference to our consolidated leverage ratio. Base rate loans will, at our election, bear interest at (i) the rate described in clause (b) above or (ii) a rate to be agreed upon by us and JPMorgan. Borrowings in Canadian dollars under the new credit facility will bear interest at (a) the Canadian deposit offered rate plus 0.10% for specified interest periods plus a margin determined with reference to our consolidated leverage ratio or (b) a floating rate equal to the greater of (i) the Canadian prime rate and (ii) the Canadian deposit offered rate for a one month interest period plus 1.00%, plus, in each case, a margin determined with reference to our consolidated leverage ratio.
Secured Revolving Credit Facility [Member]
Long Term Debt (Additional Textual) [Abstract]
Interest rate spread on notes	0.76%
Description of interest rate on credit facility	We pay interest at a rate per annum equal to a margin of 0.76%, plus LIBOR
Unsecured Private Placement Notes [Member]
Long Term Debt (Additional Textual) [Abstract]
Long-Term debt, Notes	75.0
Long-Term debt, Notes	75.0
Long term debt description of rate	The notes bear interest at 0.60% over LIBOR
Long-term debt Maturities	Jun. 30, 2015
Periodic Payment description	The notes do not require principal payments until maturity
Interest rate spread on notes	0.60%
Interest rate on notes	1.07%
Condition A in Canadian Dollars [Member] | Unsecured Revolving Credit Facility [Member]
Long Term Debt (Additional Textual) [Abstract]
Interest rate spread on notes	0.10%
Description of interest rate on credit facility	The Canadian deposit offered rate plus 0.10%, plus, in, in each case, a margined determined with reference to our consolidated leverage ratio.
Condition A-iii in US Dollars [Member] | Unsecured Revolving Credit Facility [Member]
Long Term Debt (Additional Textual) [Abstract]
Interest rate spread on notes	1.00%
Description of interest rate on credit facility	The adjusted LIBOR for a one month interest period plus 1.00%, plus, in each case, a margin determined with reference to our consolidated leverage ratio.
Condition A-ii in US Dollars [Member] | Unsecured Revolving Credit Facility [Member]
Long Term Debt (Additional Textual) [Abstract]
Interest rate spread on notes	0.50%
Description of interest rate on credit facility	Federal funds rate plus 0.50%
Condition A-ii in Canadian Dollars [Member] | Unsecured Revolving Credit Facility [Member]
Long Term Debt (Additional Textual) [Abstract]
Interest rate spread on notes	1.00%
Description of interest rate on credit facility	The Canadian deposit offered rate for a one month interest period plus 1.00, plus, in, in each case, a margined determined with reference to our consolidated leverage ratio.