Business realignment charges - Business segment information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2018 USD ($) employee	Dec. 31, 2017 USD ($) employee	Dec. 31, 2018 USD ($) employee	Dec. 31, 2017 USD ($) employee
Other expense
Restructuring Cost and Reserve [Line Items]
Realignment charges and acquisition integration costs	$ 220	$ 0	$ 275	$ 0
Diversified Industrial | Operating Segments
Restructuring Cost and Reserve [Line Items]
Realignment charges and acquisition integration costs	$ 7,382	$ 24,684	$ 15,940	$ 37,947
Number of positions eliminated (by employees) | employee	164	723	365	1,265
Aerospace Systems | Operating Segments
Restructuring Cost and Reserve [Line Items]
Realignment charges and acquisition integration costs	$ 0	$ 692	$ 0	$ 1,455
Number of positions eliminated (by employees) | employee	0	19	0	56