No Trading Symbol Flag Net Assets C000012005 [Member] Money Market Master Portfolio C000012008 [Member] Treasury Money Market Master Portfolio Investment Company, Portfolio Turnover C000012004 [Member] Diversified Equity Alpha Master Portfolio C000104371 [Member] Total International ex U.S. Index Master Portfolio C000101834 [Member] Large Cap Index Master Portfolio C000012007 [Member] S&P 500 Index Master Portfolio C000012009 [Member] U.S. Total Bond Index Master Portfolio C000135466 [Member] International Tilts Master Portfolio Investment Type [Axis] JAPAN UNITED KINGDOM FRANCE GERMANY AUSTRALIA NETHERLANDS UNITED STATES SWITZERLAND SPAIN ITALY Other [Member] Liabilities in Excess of Other Assets [Member] ASML Holding NV [Member] ABB Ltd., Class N [Member] Banco Santander SA [Member] Tokyo Electron Ltd. [Member] AstraZeneca PLC [Member] AXA SA [Member] HSBC Holdings PLC [Member] BHP Group Ltd., Class DI [Member] Siemens AG, Class N [Member] Nestle SA, Class N [Member] U.S. Treasury Obligations [Member] U.S. Government Sponsored Agency Securities [Member] Corporate Bond Securities [Member] Foreign Agency Obligations [Member] Non-Agency Mortgage-Backed Securities [Member] Municipal Bonds [Member] Capital Trusts [Member] Asset-Backed Securities [Member] AAA/Aaa [Member] AA/Aa [Member] A [Member] BBB/Baa [Member] N/R [Member] Financial Services Sector [Member] Healthcare Sector [Member] Energy Sector [Member] Short-Term Securities [Member] NVIDIA Corp. [Member] Apple, Inc. [Member] Microsoft Corp. [Member] Amazon.com, Inc. [Member] Alphabet, Inc., Class A [Member] Broadcom, Inc. [Member] Alphabet, Inc., Class C [Member] Micron Technology, Inc. [Member] Meta Platforms, Inc., Class A [Member] Tesla, Inc. [Member] Real Estate Sector [Member] TAIWAN KOREA, REPUBLIC OF CANADA CHINA Taiwan Semiconductor Manufacturing Co. Ltd. [Member] Samsung Electronics Co. Ltd. [Member] SK Hynix, Inc. [Member] Tencent Holdings Ltd. [Member] Royal Bank of Canada [Member] Novartis AG, Class N [Member] Roche Holding AG [Member] Other Assets Less Liabilities [Member] Repurchase Agreements [Member] Commercial Paper [Member] Time Deposits [Member] Certificates of Deposit [Member]