Expense Example, No Redemption - SelectPortfoliosFidelityAdvisorMaterialsFund-AMCIZPRO - SelectPortfoliosFidelityAdvisorMaterialsFund-AMCIZPRO - Select Materials Portfolio	Apr. 29, 2024 USD ($)
Fidelity Advisor Materials Fund - Class A
Expense Example, No Redemption:
1 Year	$ 670
3 Years	872
5 Years	1,091
10 Years	1,718
Fidelity Advisor Materials Fund - Class C
Expense Example, No Redemption:
1 Year	177
3 Years	548
5 Years	944
10 Years	1,853
Fidelity Advisor Materials Fund - Class M
Expense Example, No Redemption:
1 Year	472
3 Years	730
5 Years	1,007
10 Years	1,797
Fidelity Advisor Materials Fund - Class I
Expense Example, No Redemption:
1 Year	74
3 Years	230
5 Years	401
10 Years	894
Fidelity Advisor Materials Fund - Class Z
Expense Example, No Redemption:
1 Year	59
3 Years	186
5 Years	324
10 Years	$ 726