Share repurchase program Share repurchase program (Details) - $ / shares	3 Months Ended	6 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Oct. 22, 2014
Equity, Class of Treasury Stock
Stock Repurchase Program, Number of Shares Authorized to be Repurchased			35,000,000
Shares repurchased (in shares)	893,010	3,663,634
Treasury Stock Acquired, Average Cost Per Share	$ 100.78	$ 109.18