Significant Accounting Policies - Computer Software Development Costs (Details) - Computer Software Development Costs - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Computer Software Development Costs for Internal Use
Maximum period over which amortization of computer software development costs provided on a product-by-product basis using straight-line method	3 years
Computer software cost capitalized	$ 0.4	$ 0.3	$ 0.4
Amortization expense charged to operations	0.5	0.6	$ 0.7
Computer software development accumulated amortization	$ 74.3	$ 73.8
Weighted average remaining useful life of computer software development costs	7 months 9 days	8 months 1 day