Short Term Investments Quality [Member] Mortgage Backed Security Issued by US Government Sponsored Enterprise Quality [Member] US Government Debt Securities Quality [Member] US Government Corporations and Agencies Securities Quality [Member] Foreign government obligations [Member] C000008885 [Member] Class NAV C000008886 [Member] Class 1 Mortgage-Backed Securities, Issued by Private Enterprises [Member] Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member] Asset-Backed Securities [Member] Short-Term Investments [Member] US Government Debt Securities [Member] US Government Corporations and Agencies Securities [Member] Municipal Bonds [Member] Corporate Bond Securities [Member] Standard & Poor's, BB Rating [Member] Standard & Poor's, BBB Rating [Member] Standard & Poor's, A Rating [Member] Standard & Poor's, AA Rating [Member] Moody's, Aaa Rating [Member] Energy Sector [Member] Financial Services Sector [Member] Healthcare Sector [Member] Real Estate Sector [Member] C000073278 [Member] Corning Inc [Member] The Middleby Corp [Member] The Cooper Companies Inc [Member] StandardAero Inc [Member] Corpay Inc [Member] Esab Corp [Member] Hexcel Corp [Member] Advance Auto Parts Inc [Member] Lazard Inc [Member] Lamb Weston Holdings Inc [Member] Short term investments and other [Member] Term loans [Member] Revvity Inc [Member] CenterPoint Energy Inc [Member] Meta Platforms Inc Class A [Member] Alphabet Inc Class A [Member] U S Treasury Note 3 500 11 30 2030 [Member] NVIDIA Corp [Member] U S Treasury Note 3 625 10 31 2030 [Member] Apple Inc [Member] Amazon com Inc [Member] Microsoft Corp [Member] C000095456 [Member] Common Stock [Member] AUSTRALIA CANADA CHINA FRANCE GERMANY JAPAN KOREA, REPUBLIC OF SWITZERLAND TAIWAN UNITED KINGDOM C000173477 [Member] Taiwan Semiconductor Manufacturing Company Ltd [Member] Samsung Electronics Company Ltd [Member] ASML Holding NV [Member] Tencent Holdings Ltd [Member] SK Hynix Inc [Member] Roche Holding AG [Member] AstraZeneca PLC [Member] HSBC Holdings PLC [Member] Novartis AG [Member] Alibaba Group Holding Ltd [Member] Other countries [Member] Berkshire Hathaway Inc Class B [Member] Tesla Inc [Member] Alphabet Inc Class C [Member] Broadcom Inc [Member] C000173478 [Member] Investment Type [Axis] Net Assets Investment Company Portfolio Turnover No Trading Symbol Flag