IDT Financial Services Holding Limited Assets and Liabilities Held for Sale (Details) - USD ($) $ in Thousands	Oct. 31, 2018	Jul. 31, 2018
Current assets held for sale:
Cash and cash equivalents	$ 4,906	$ 5,892
Restricted cash and cash equivalents	130,738	128,931
Total current assets held for sale	138,466	137,272
Noncurrent assets held for sale:
Other assets	5,920	5,706
Current liabilities held for sale:
Total current liabilities held for sale	130,550	128,770
Noncurrent liabilities held for sale:
Total noncurrent liabilities held for sale	497	542
IDTFS Holding [Member]
Current assets held for sale:
Cash and cash equivalents	4,906	5,892
Restricted cash and cash equivalents	130,738	128,931
Trade accounts receivable, net of allowance for doubtful accounts of $2,027 and $2,192 at October 31, 2018 and July 31, 2018, respectively	2,328	1,265
Prepaid expenses	289	1,016
Other current assets	205	168
Total current assets held for sale	138,466	137,272
Noncurrent assets held for sale:
Property, plant and equipment, net	5	12
Other intangibles, net	178	190
Other assets	5,737	5,504
Total noncurrent assets held for sale	5,920	5,706
Current liabilities held for sale:
Trade accounts payable	665	776
Accrued expenses	283	407
Deferred revenue	56	12
Customer deposits	129,542	127,571
Other current liabilities	4	4
Total current liabilities held for sale	130,550	128,770
Noncurrent liabilities held for sale:
Other liabilities	497	542
Total noncurrent liabilities held for sale	$ 497	$ 542