Expense Example	Jun. 30, 2026 USD ($)
U.S. Diversified Real Estate ETF \| U.S. Diversified Real Estate ETF Class
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 54
Expense Example, with Redemption, 3 Years	170
Expense Example, with Redemption, 5 Years	296
Expense Example, with Redemption, 10 Years	665
The Frontier Economic Fund \| The Frontier Economic Fund Class
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	20
Expense Example, with Redemption, 3 Years	64
Expense Example, with Redemption, 5 Years	113
Expense Example, with Redemption, 10 Years	$ 255

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 4

Name:	oef_ExpenseExampleYear01
Namespace Prefix:	oef_
Data Type:	dtr-types:nonNegativeMonetaryItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 4

Name:	oef_ExpenseExampleYear03
Namespace Prefix:	oef_
Data Type:	dtr-types:nonNegativeMonetaryItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 4

Name:	oef_ExpenseExampleYear05
Namespace Prefix:	oef_
Data Type:	dtr-types:nonNegativeMonetaryItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 4

Name:	oef_ExpenseExampleYear10
Namespace Prefix:	oef_
Data Type:	dtr-types:nonNegativeMonetaryItemType
Balance Type:	na
Period Type:	duration

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 1
-Subsection a

Name:	dei_LegalEntityAxis=ck0001540305_S000061208Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=ck0001540305_S000093209Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: