Other Operating Expense, Net (Details) - Straight Path [Member] - USD ($) $ in Millions	3 Months Ended
Oct. 31, 2020	Oct. 31, 2019
Other Operating Expense, Net (Details) [Line Items]
Legal fees	$ 0.3	$ 0.7
Recorded gains from insurance	$ 0.6	$ 0.4

The amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

Name:	us-gaap_LegalFees
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration