Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 418,007	$ 394,261	$ 270,360
Comprehensive income, net of tax:
Comprehensive income	410,755	402,779	229,959
Comprehensive income attributable to noncontrolling interest	140	34	0
Comprehensive income attributable to Copart, Inc.	410,615	402,745	229,959
Other comprehensive income:
Unrealized gain on interest rate swaps, net	0	0	603
Reclassification adjustment of interest rate swaps, net	0	0	(320)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(7,252)	8,518	(40,684)
Tax effects on unrealized gain (loss) on interest rate swaps	0	0	342
Tax effects on reclassification adjustment of interest rate swaps	$ 0	$ 0	$ (178)