Reconciliation Between Basic and Diluted Net Income Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Reconciliation Of Earning Per Share Statement [Line Items]
Net income attributable to Xcerra	$ 7,931	$ 2,572	$ 25,462	$ 2,590
Basic EPS:
Weighted average shares outstanding- basic	54,836	54,120	54,720	53,993
Basic net income per share	$ 0.14	$ 0.05	$ 0.47	$ 0.05
Diluted EPS:
Weighted average shares outstanding- basic	54,836	54,120	54,720	53,993
Plus: impact of unvested RSUs	614	442	939	479
Weighted average shares outstanding- diluted	55,450	54,562	55,659	54,472
Diluted net income per share	$ 0.14	$ 0.05	$ 0.46	$ 0.05