Business realignment and acquisition integration charges - Business segment information (Details) $ in Thousands	3 Months Ended
	Sep. 30, 2019 USD ($) employee	Sep. 30, 2018 USD ($) employee
Corporate general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Realignment charges and acquisition integration costs	$ 5	$ 0
Number of positions eliminated (employees) | employee	1	0
Other expense
Restructuring Cost and Reserve [Line Items]
Realignment charges and acquisition integration costs	$ 0	$ 55
Diversified Industrial | Operating Segments
Restructuring Cost and Reserve [Line Items]
Realignment charges and acquisition integration costs	$ 4,725	$ 8,558
Number of positions eliminated (employees) | employee	219	201
Aerospace Systems | Operating Segments
Restructuring Cost and Reserve [Line Items]
Realignment charges and acquisition integration costs	$ (7)	$ 0