Label	Element	Value
ETFB Green SRI REITs ETF \| Prologis, Inc. [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	9.40%
ETFB Green SRI REITs ETF \| Welltower, Inc. [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	9.10%
ETFB Green SRI REITs ETF \| Digital Realty Trust, Inc. [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	8.70%
ETFB Green SRI REITs ETF \| Public Storage [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	7.90%
ETFB Green SRI REITs ETF \| AvalonBay Communities, Inc. [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	6.60%
ETFB Green SRI REITs ETF \| Alexandria Real Estate Equities, Inc. [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	4.70%
ETFB Green SRI REITs ETF \| Equity Residential [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	4.60%
ETFB Green SRI REITs ETF \| Goodman Group [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	4.20%
ETFB Green SRI REITs ETF \| Nippon Prologis REIT, Inc. [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	3.40%
ETFB Green SRI REITs ETF \| Invitation Homes, Inc. [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	3.30%
ETFB Green SRI REITs ETF \| Financial [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	98.70%
ETFB Green SRI REITs ETF \| Cash & Other [Member]
Holdings [Line Items]	oef_HoldingsLineItems
Percent of Net Asset Value	oef_PctOfNav	1.30%