Corporate Investments and Funds Held For Clients - Maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018
Expected maturities of available-for-sale securities, amortized cost
One year or less	$ 126,192
One year to two years	16,064
Two years to three years	1,500
Total available-for-sale securities	143,756	$ 123,991
Expected maturities of available-for-sale securities, fair value
One year or less	126,062
One year to two years	16,028
Two years to three years	1,505
Total available-for-sale securities	$ 143,595	$ 123,808