Income Taxes (Details 3) - USD ($) $ in Thousands	Jul. 31, 2020	Jul. 31, 2019
Deferred tax assets:
Allowance for doubtful accounts	$ 1,141	$ 919
Accrued compensation and benefits	13,217	18,397
State taxes	460	559
Accrued other	4,763	3,312
Deferred revenue	(1,950)	(1,322)
Losses carried forward	15,092	7,631
Federal tax benefit	9,872	7,998
Total gross deferred tax assets	46,495	40,138
Less: Valuation allowance	(15,429)	(8,578)
Net deferred tax assets	31,066	31,560
Deferred tax liabilities:
Vehicle pooling costs	(15,291)	(15,731)
Property and equipment	(62,123)	(38,475)
Prepaid insurance	(1,411)	(987)
Intangibles and goodwill	(23,714)	(24,639)
Total gross deferred tax liabilities	(102,539)	(79,832)
Net deferred tax liabilities	(71,473)	(48,272)
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 29,000	$ 22,000