XML 74 R46.htm IDEA: XBRL DOCUMENT v3.21.2

Summary of Significant Accounting Policies Revenues (Details)	Jun. 30, 2021 Units
Accounting Policies [Abstract]
Number of customers with billing dates before month end	5

X

- Definition

Number of customers with billing dates before month end

+ References

No definition available.

+ Details

Name:	tve_NumberOfCustomersWithBillingDatesBeforeMonthEnd
Namespace Prefix:	tve_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- References

No definition available.

+ Details

Name:	us-gaap_AccountingPoliciesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration