S000013702 [Member] Average Annual Total Returns |
12 Months Ended | 60 Months Ended | 120 Months Ended | 214 Months Ended | ||
|---|---|---|---|---|---|---|
Dec. 31, 2024 |
Dec. 31, 2024 |
Dec. 31, 2024 |
Dec. 31, 2024 |
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| Bloomberg U.S. Universal Index (Returns do not reflect deductions for fees, expenses or taxes) | ||||||
| Prospectus [Line Items] | ||||||
| Average Annual Return, Percent | [1] | 2.04% | 0.06% | 1.73% | ||
| Bloomberg U.S. MBS Index (Returns do not reflect deductions for fees, expenses or taxes) | ||||||
| Prospectus [Line Items] | ||||||
| Average Annual Return, Percent | 1.20% | (0.74%) | 0.91% | |||
| iShares MBS ETF | ||||||
| Prospectus [Line Items] | ||||||
| Average Annual Return, Percent | 1.31% | (0.75%) | 0.80% | |||
| Performance Inception Date | Mar. 13, 2007 | |||||
| iShares MBS ETF | After Taxes on Distributions | ||||||
| Prospectus [Line Items] | ||||||
| Average Annual Return, Percent | (0.28%) | (1.76%) | (0.25%) | |||
| iShares MBS ETF | After Taxes on Distributions and Sales | ||||||
| Prospectus [Line Items] | ||||||
| Average Annual Return, Percent | 0.77% | (0.98%) | 0.17% | |||
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