Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 394,261	$ 270,360	$ 219,783
Comprehensive income, net of tax:
Comprehensive income	402,779	229,959	171,050
Comprehensive income attributable to noncontrolling interest	34	0	0
Comprehensive income attributable to Copart, Inc.	402,745	229,959	171,050
Other comprehensive income:
Unrealized gain on interest rate swaps, net	0	603	1,926
Reclassification adjustment of interest rate swaps, net	0	(320)	(1,141)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	8,518	(40,684)	(49,518)
Tax effects on unrealized gain (loss) on interest rate swaps	0	(342)	(1,026)
Tax effects on reclassification adjustment of interest rate swaps	$ 0	$ 178	$ 582