Segment and Related Information - Summary of Assets by Geographical Region (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Net equipment, leasehold improvements and property	$ 43.2	$ 51.1
Total assets	1,174.1	1,208.9
United States [Member]
Segment Reporting Information [Line Items]
Net equipment, leasehold improvements and property	20.0	27.6
Total assets	852.3	897.3
Rest of World [Member]
Segment Reporting Information [Line Items]
Net equipment, leasehold improvements and property	23.2	23.5
Total assets	110.5	112.4
Reportable Geographical Components [Member]
Segment Reporting Information [Line Items]
Total assets	$ 962.8	$ 1,009.7