Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	4 Months Ended	8 Months Ended	12 Months Ended			32 Months Ended
	Dec. 31, 2017	Aug. 31, 2018	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2018	Aug. 31, 2020
Domestic and foreign pre-tax income
United States			$ 42,027	$ 37,088	$ 48,962
Foreign			3,293	6,465	8,003
Income before income taxes			45,320	43,553	56,965
Current:
Federal			9,157	9,880	12,872
State			1,813	1,699	1,662
Foreign			962	1,575	1,761
Total current income tax provision			11,932	13,154	16,295
Deferred:
Federal			(520)	(1,699)	(2,214)
State			(184)	(529)	(263)
Foreign			(65)	(84)	4
Total deferred income tax provision (benefit)			(769)	(2,312)	(2,473)
Total income tax provision			$ 11,163	$ 10,842	$ 13,822
Reconciliation of the effective income tax rate on continuing operations with the U.S. federal statutory income tax rate
Federal statutory rates (as a percent)	35.00%	21.00%	21.00%	21.00%	25.70%	21.00%
Adjustment resulting from the tax effect of:
State and local taxes, net of federal benefit (as a percent)			3.00%	2.10%	1.90%
Domestic production deduction (as a percent)			(0.00%)	(0.00%)	(1.60%)
Foreign tax rate differential (as a percent)			0.00%	0.10%	(0.30%)
Adjustment to uncertain tax position (as a percent)			1.10%	(1.00%)	(1.10%)
Transaction costs not deductible			0.50%	0.00%	0.00%
Research credit generated (as a percent)			(0.10%)	(0.30%)	(0.20%)
Stock Compensation (as a percent)			(0.30%)	(0.40%)	(3.40%)
Permanent items (as a percent)			0.90%	1.10%	0.90%
Tax effect of undistributed earnings (as a percent)			0.30%	0.60%	(0.80%)
Other (as a percent)			0.40%	(0.40%)	(0.80%)
Change in valuation allowance (as a percent)			0.00%	0.10%	0.10%
Deferred income tax remeasurement (as a percent)			0.00%	0.00%	1.70%
Effective income tax rate (as a percent)			24.60%	24.90%	24.30%