Employee post-retirement benefits (Narrative) (Details) - 9 months ended Mar. 31, 2016 $ / shares in Units, ¥ in Millions	USD ($) $ / shares shares	CNY (¥) shares
Employee Post-retirement Benefits 1	20.00%	20.00%
Employee Post-retirement Benefits 2	8.00%	8.00%
Employee Post-retirement Benefits 3	$ 200,000
Employee Post-retirement Benefits 4	600,000
Employee Post-retirement Benefits 5	$ 800,000
Employee Post-retirement Benefits 6 | shares	280,000	280,000
Employee Post-retirement Benefits 7 | shares	65,102	65,102
Employee Post-retirement Benefits 8 | $ / shares	$ 4.99
Employee Post-retirement Benefits 9	$ 324,860
Employee Post-retirement Benefits 10 | ¥		¥ 2.0
Employee Post-retirement Benefits 11 | shares	202,086	202,086
Employee Post-retirement Benefits 12 | $ / shares	$ 4.17
Employee Post-retirement Benefits 13	$ 842,692
Employee Post-retirement Benefits 14 | ¥		¥ 5.2