Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Federal tax rate			21.00%		35.00%
Income tax (benefit) expense	$ 4,483	$ 1,335	$ 7,612	$ (7,046)
(Loss) income from operations before income taxes	16,866	10,468	27,474	20,040
Excess tax benefits on stock-based compensation	$ 67	$ 294	1,716	$ 7,579
Deferred tax assets, effect of Tax Cuts and Jobs Act, tax expense (benefit)			$ 1,711