Income Taxes - Components of Income Before Income Taxes and Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Income before income taxes:
United States									$ 43,368	$ 30,499	$ 25,194
Foreign									(795)	569	92
Income before income taxes	$ 16,628	$ 5,905	$ 10,468	$ 9,572	$ 11,307	$ 10,218	$ 6,983	$ 2,560	42,573	31,068	25,286
Federal:
Current									4,470	11,476	6,707
Deferred									(4,527)	(7,645)	(2,627)
Federal Income Tax Expense (Benefit), Continuing Operations, Total									(57)	3,831	4,080
State:
Current									2,370	3,650	1,839
Deferred									(537)	(1,684)	(424)
State and Local Income Tax Expense (Benefit), Continuing Operations, Total									1,833	1,966	1,415
Foreign:
Current									186	240	59
Deferred									(272)	156	(10)
Foreign, Income Tax expense benefit									(86)	396	49
Income tax expense (benefit)	$ 6,527	$ 2,209	$ 1,335	$ (8,381)	$ 2,503	$ 3,170	$ 1,779	$ (1,259)	$ 1,690	$ 6,193	$ 5,544