Organization	9 Months Ended
Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization Morgan Stanley Smith Barney Spectrum Select L.P. (the “Partnership”) is a Delaware limited partnership organized in 1991 to engage primarily in the speculative trading of futures contracts, options on futures and forward contracts, and forward contracts on physical commodities and other commodity interests, including, but not limited to, foreign currencies, financial instruments, metals, energy, and agricultural products (collectively, “Futures Interests”) (refer to Note 5. Financial Instruments). The Partnership is one of the Morgan Stanley Spectrum series of funds, comprised of the Partnership, Morgan Stanley Smith Barney Spectrum Currency and Commodity L.P., Morgan Stanley Smith Barney Spectrum Technical L.P. and Morgan Stanley Smith Barney Spectrum Strategic L.P. Ceres Managed Futures LLC, a Delaware limited liability company, acts as the general partner (“Ceres” or the “General Partner”) and commodity pool operator for the Partnership. Ceres is a wholly-owned subsidiary of Morgan Stanley Smith Barney Holdings LLC (“MSSBH”). MSSBH is wholly-owned indirectly by Morgan Stanley. Morgan Stanley Smith Barney LLC is doing business as Morgan Stanley Wealth Management (“Morgan Stanley Wealth Management”). Morgan Stanley Wealth Management is a principal subsidiary of MSSBH. The clearing commodity broker for the Partnership is Morgan Stanley & Co. LLC (“MS&Co.”). MS&Co. also acts as the counterparty on all trading of foreign currency forward contracts. MS&Co. is a wholly-owned subsidiary of Morgan Stanley. The trading advisors to the Partnership are Altis Partners (Jersey) Limited (“Altis”), EMC Capital Management, Inc. (“EMC”), Graham Capital Management, L.P. (“Graham”) and Rabar Market Research, Inc. (“Rabar”) (individually, a “Trading Advisor”, or collectively, the “Trading Advisors”). During June 2015, the General Partner determined to invest a portion of the Partnership’s excess cash (the Partnership’s assets not used for futures interest trading or required margin for such trading) in United States (“U.S.”) Treasury bills and/or other permitted investments. The Partnership will receive interest on U.S. Treasury bills or other permitted investments at the relevant coupon rate. There will be no change to the treatment of the excess cash not invested in U.S. Treasury bills or other permitted investments. The General Partner intends to hold the U.S. Treasury bills until maturity, but in the event that the General Partner is required to liquidate U.S. Treasury bills before they mature, to meet redemption requests or otherwise, the Partnership may incur a loss on such U.S. Treasury bills and/or may be subject to additional fees or other costs. The General Partner will endeavor to maintain sufficient cash in the Partnership’s accounts in order to avoid early liquidation of U.S. Treasury bills. In July 2015, the General Partner delegated certain administrative functions to SS&C Technologies, Inc., a Delaware corporation, currently doing business as SS&C GlobeOp (the “Administrator”). Pursuant to a master services agreement, the Administrator furnishes certain administrative services in connection with the operation of the Partnership, including the preparation of required books and records and reports to limited partners, government agencies and regulators; computation of net asset value; assistance in connection with certain limited partner communications; calculation and accrual of income, expenses, gains and losses; preparation of financial, performance and other reporting; coordination of the annual audit with the Partnership’s auditor; preparation of the Partnership’s draft annual financial statements and accompanying materials; assistance with updating periodic regulatory filings; provision of tax services as agreed with the General Partner; assistance in opening and operating the Partnership’s bank accounts; provision of daily profit and loss, estimated net asset value and position and reconciliation reports; and reconciliation of daily transactions, positions and cash balances to the Partnership’s brokerage and bank accounts. In addition, the Administrator will maintain certain books and records of the Partnership. The General Partner pays or reimburses the Partnership, from the General Partner fee (formerly, the administrative fee) it receives, the ordinary administrative expenses of the Partnership. This includes the expenses related to the engagement of the Administrator. Therefore, the engagement of the Administrator will not impact the Partnership’s break-even point.

1. Organization

Morgan Stanley Smith Barney Spectrum Select L.P. (the “Partnership”) is a Delaware limited partnership organized in 1991 to engage primarily in the speculative trading of futures contracts, options on futures and forward contracts, and forward contracts on physical commodities and other commodity interests, including, but not limited to, foreign currencies, financial instruments, metals, energy, and agricultural products (collectively, “Futures Interests”) (refer to Note 5. Financial Instruments). The Partnership is one of the Morgan Stanley Spectrum series of funds, comprised of the Partnership, Morgan Stanley Smith Barney Spectrum Currency and Commodity L.P., Morgan Stanley Smith Barney Spectrum Technical L.P. and Morgan Stanley Smith Barney Spectrum Strategic L.P.

Ceres Managed Futures LLC, a Delaware limited liability company, acts as the general partner (“Ceres” or the “General Partner”) and commodity pool operator for the Partnership. Ceres is a wholly-owned subsidiary of Morgan Stanley Smith Barney Holdings LLC (“MSSBH”). MSSBH is wholly-owned indirectly by Morgan Stanley. Morgan Stanley Smith Barney LLC is doing business as Morgan Stanley Wealth Management (“Morgan Stanley Wealth Management”). Morgan Stanley Wealth Management is a principal subsidiary of MSSBH.

The clearing commodity broker for the Partnership is Morgan Stanley & Co. LLC (“MS&Co.”). MS&Co. also acts as the counterparty on all trading of foreign currency forward contracts. MS&Co. is a wholly-owned subsidiary of Morgan Stanley. The trading advisors to the Partnership are Altis Partners (Jersey) Limited (“Altis”), EMC Capital Management, Inc. (“EMC”), Graham Capital Management, L.P. (“Graham”) and Rabar Market Research, Inc. (“Rabar”) (individually, a “Trading Advisor”, or collectively, the “Trading Advisors”).

During June 2015, the General Partner determined to invest a portion of the Partnership’s excess cash (the Partnership’s assets not used for futures interest trading or required margin for such trading) in United States (“U.S.”) Treasury bills and/or other permitted investments. The Partnership will receive interest on U.S. Treasury bills or other permitted investments at the relevant coupon rate. There will be no change to the treatment of the excess cash not invested in U.S. Treasury bills or other permitted investments. The General Partner intends to hold the U.S. Treasury bills until maturity, but in the event that the General Partner is required to liquidate U.S. Treasury bills before they mature, to meet redemption requests or otherwise, the Partnership may incur a loss on such U.S. Treasury bills and/or may be subject to additional fees or other costs. The General Partner will endeavor to maintain sufficient cash in the Partnership’s accounts in order to avoid early liquidation of U.S. Treasury bills.

In July 2015, the General Partner delegated certain administrative functions to SS&C Technologies, Inc., a Delaware corporation, currently doing business as SS&C GlobeOp (the “Administrator”). Pursuant to a master services agreement, the Administrator furnishes certain administrative services in connection with the operation of the Partnership, including the preparation of required books and records and reports to limited partners, government agencies and regulators; computation of net asset value; assistance in connection with certain limited partner communications; calculation and accrual of income, expenses, gains and losses; preparation of financial, performance and other reporting; coordination of the annual audit with the Partnership’s auditor; preparation of the Partnership’s draft annual financial statements and accompanying materials; assistance with updating periodic regulatory filings; provision of tax services as agreed with the General Partner; assistance in opening and operating the Partnership’s bank accounts; provision of daily profit and loss, estimated net asset value and position and reconciliation reports; and reconciliation of daily transactions, positions and cash balances to the Partnership’s brokerage and bank accounts. In addition, the Administrator will maintain certain books and records of the Partnership. The General Partner pays or reimburses the Partnership, from the General Partner fee (formerly, the administrative fee) it receives, the ordinary administrative expenses of the Partnership. This includes the expenses related to the engagement of the Administrator. Therefore, the engagement of the Administrator will not impact the Partnership’s break-even point.