Name:	nsfdf_ChangeInNoncashWorkingCapitalBalances
Namespace Prefix:	nsfdf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The increase (decrease) during the reporting period in the amounts payable to vendors for goods and services received and the amount of obligations and expenses incurred but not paid.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585

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

The increase (decrease) during the reporting period in amount due within one year (or one business cycle) from customers for the credit sale of goods and services.

Name:	us-gaap_IncreaseDecreaseInAccountsReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Amount of increase (decrease) in obligation to transfer good or service to customer for which consideration has been received or is receivable.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 912
-SubTopic 310
-Section 45
-Paragraph 11
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126938201&loc=d3e55415-109406

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

The increase (decrease) during the reporting period of the amounts due from borrowers for outstanding secured or unsecured loans evidenced by a note.

Name:	us-gaap_IncreaseDecreaseInNotesReceivables
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The increase (decrease) during the reporting period in the amount of outstanding money paid in advance for goods or services that bring economic benefits for future periods.