Business Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2016	Jan. 31, 2015
Segment Reporting Information [Line Items]
Revenues	$ 382,454	$ 394,173	$ 773,032	$ 807,051
Income (loss) from operations	$ 6,377	3,735	$ 14,303	83,344
Gain on sale of interest in Fabrix Systems Ltd.		484		75,629
Operating Segments [Member] \| Telecom Platform Services [Member]
Segment Reporting Information [Line Items]
Revenues	$ 376,692	388,970	$ 762,380	792,758
Income (loss) from operations	6,302	$ 6,870	16,027	$ 12,540
Gain on sale of interest in Fabrix Systems Ltd.
Operating Segments [Member] \| Consumer Phone Services [Member]
Segment Reporting Information [Line Items]
Revenues	1,766	$ 2,243	3,595	$ 4,554
Income (loss) from operations	289	$ 306	629	$ 662
Gain on sale of interest in Fabrix Systems Ltd.
Operating Segments [Member] \| All Other [Member]
Segment Reporting Information [Line Items]
Revenues	3,996	$ 2,960	7,057	$ 9,739
Income (loss) from operations	$ 1,845	(602)	$ 2,275	75,936
Gain on sale of interest in Fabrix Systems Ltd.		$ 484		$ 75,629
Operating Segments [Member] \| Corporate [Member]
Segment Reporting Information [Line Items]
Revenues
Income (loss) from operations	$ (2,059)	$ (2,839)	$ (4,628)	$ (5,794)
Gain on sale of interest in Fabrix Systems Ltd.

Amount of gain (loss) on sale or disposal of equity in securities of subsidiaries.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (13)(g)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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