The Fund seeks to achieve its investment objective by investing primarily in domestic and foreign debt securities that the sub-adviser, Wellington Management Company LLP, considers to be attractive from a yield perspective while considering total return. The Fund normally invests in non-investment grade debt securities and highly rated securities. The foreign debt securities in which the Fund invests include securities of emerging market issuers. The Fund may invest in various types of debt securities, including, but not limited to, corporate bonds; debt securities issued by foreign governments; U.S. government and agency securities; bank loans or loan participation interests in secured, second lien or unsecured variable, fixed or floating rate loans; and securitized debt. The Fund may use derivatives including futures contracts, swaps, options and forward foreign currency contracts, to manage portfolio risk, for efficient replication of securities the Fund could buy or for other investment purposes. The Fund seeks to be diversified across sectors, although the Fund is not required to invest in all sectors at all times and may invest 100% of its net assets in one sector if conditions warrant. The Fund may purchase or sell securities on a when-issued, delayed delivery or forward commitment basis, including securities acquired or sold in the to be announced market. The Fund may invest in certain restricted securities, such as securities that are only eligible for resale pursuant to Rule 144A, and securities of U.S. and non-U.S. issuers that are issued pursuant to Regulation S. The Fund may trade securities actively and may invest in debt securities of any maturity or duration. There is no limit on the average maturity of the Funds portfolio. The portfolio managers may allocate a portion of the Funds assets to specialists within Wellington Management who drive individual sector and security selection strategies.