Restructuring (Details) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2017 USD ($) facility	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)
Restructuring
Lease buyout	$ 0.7	$ 0.0	$ 0.0
Facility closing
Restructuring
Number of facilities being exited | facility	3
Exit costs	$ 5.4
Lease liability current	1.7
Lease liability noncurrent	3.7
Accelerated depreciation	1.4
Deferred rent and tenant improvements written off	1.9
Net impact of facility exit activity	$ 4.9