Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2016	Apr. 30, 2015
Segment Reporting Information [Line Items]
Revenues	$ 355,154	$ 383,930	$ 1,128,186	$ 1,190,981
Income (loss) from operations	5,676	2,470	19,978	85,813
Gain on sale of interest in Fabrix Systems Ltd.	1,086	1,235	1,086	76,864
Operating Segments [Member] | Telecom Platform Services [Member]
Segment Reporting Information [Line Items]
Revenues	350,399	379,139	1,112,779	1,171,897
Income (loss) from operations	$ 6,319	$ 5,602	$ 22,346	$ 18,142
Gain on sale of interest in Fabrix Systems Ltd.
Operating Segments [Member] | Consumer Phone Services [Member]
Segment Reporting Information [Line Items]
Revenues	$ 1,682	$ 2,098	$ 5,277	$ 6,652
Income (loss) from operations	$ 351	$ 324	$ 980	$ 985
Gain on sale of interest in Fabrix Systems Ltd.
Operating Segments [Member] | All Other [Member]
Segment Reporting Information [Line Items]
Revenues	$ 3,073	$ 2,693	$ 10,130	$ 12,432
Income (loss) from operations	1,804	1,584	4,079	77,520
Gain on sale of interest in Fabrix Systems Ltd.	$ 1,086	$ 1,235	$ 1,086	$ 76,864
Operating Segments [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Revenues
Income (loss) from operations	$ (2,798)	$ (5,040)	$ (7,427)	$ (10,834)
Gain on sale of interest in Fabrix Systems Ltd.