Summary of Total Interest Expense Recognized (Detail) - 0.25% Convertible Senior Note Due 2022 - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Debt Instrument [Line Items]
0.25% contractual coupon	$ 216	$ 216	$ 656	$ 513
Amortization of debt discount and debt issuance costs including initial purchaser discount	3,112	2,974	9,367	7,017
Interest expense	$ 3,328	$ 3,190	$ 10,023	$ 7,530