Income Taxes (Details 3) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Deferred tax assets:
Allowance for doubtful accounts	$ 1,013	$ 1,063
Accrued compensation and benefits	23,902	18,249
State taxes	625	1,488
Accrued other	2,634	3,006
Deferred revenue	2,056
Property and equipment	10,969	3,378
Losses carried forward	1,028	398
Long-term note write off
Federal tax benefit	7,989	5,758
Total gross deferred tax assets	50,216	33,340
Less valuation allowance	(1,211)	(948)
Net deferred tax assets	49,005	32,392
Deferred tax liabilities:
Vehicle pooling costs	(4,537)	(4,956)
Prepaid insurance	(792)	(1,397)
Deferred revenue		(1,721)
Intangibles and goodwill	(24,758)	(25,031)
Workers compensation	(224)	(359)
Total gross deferred tax liabilities	(30,311)	(33,464)
Net deferred tax asset (liability)	$ 18,694	$ (1,072)

The tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to Federal tax benefit recognized only for tax purposes and which will reverse when recognized under generally accepted accounting principles.

No definition available.