Net Assets Investment Company, Portfolio Turnover C000008448 [Member] iShares MSCI EAFE International Index Fund - Institutional Shares C000008447 [Member] iShares MSCI EAFE International Index Fund - Investor A Shares C000201956 [Member] iShares MSCI EAFE International Index Fund - Investor P Shares C000244427 [Member] iShares MSCI EAFE International Index Fund - Class G Shares [Member] C000099168 [Member] iShares MSCI EAFE International Index Fund - Class K Shares [Member] C000008452 [Member] iShares Russell 2000 Small-Cap Index Fund Institutional Shares [Member] C000008451 [Member] iShares Russell 2000 Small-Cap Index Fund Investor A Shares [Member] C000201957 [Member] iShares Russell 2000 Small-Cap Index Fund Investor P Shares [Member] C000099169 [Member] iShares Russell 2000 Small-Cap Index Fund - Class K Shares Investment Type [Axis] Other [Member] Other Other Assets Less Liabilities [Member] JAPAN UNITED KINGDOM FRANCE GERMANY SWITZERLAND AUSTRALIA NETHERLANDS UNITED STATES SPAIN ITALY ASML Holding NV [Member] HSBC Holdings PLC [Member] Roche Holding AG [Member] Novartis AG, Class N [Member] AstraZeneca PLC [Member] Nestle SA, Class N [Member] Siemens AG, Class N [Member] Shell PLC [Member] Tokyo Electron Ltd. [Member] Mitsubishi UFJ Financial Group, Inc. [Member]