Annual Operating Expenses - FidelitySustainabilityIndexFunds-ComboPRO - FidelitySustainabilityIndexFunds-ComboPRO - Fidelity International Sustainability Index Fund - Fidelity International Sustainability Index Fund	Dec. 30, 2024
Operating Expenses:
Management fee	0.20%
Distribution and/or Service (12b-1) fees	none
Other expenses	none
Total annual operating expenses	0.20%