Reserves and dividends (Narrative) (Details)	9 Months Ended
	Mar. 31, 2016 USD ($)
Reserves And Dividends 1	10.00%
Reserves And Dividends 2	50.00%
Reserves And Dividends 3	50.00%
Reserves And Dividends 4	$ 2,000,000.0
Reserves And Dividends 5	$ 2,100,000.0
Reserves And Dividends 6	25.00%