Shareholder Report, Holdings (Details)	Jun. 30, 2026
C000004007 \| Top10HoldingGovernment of JapanBNY-BR51DF2
Holdings [Line Items]
Percent of Net Asset Value	7.10%
C000004007 \| Top10HoldingPeople's Republic of ChinaBNY-BVBHMF5
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000004007 \| Top10HoldingGovernment of Japan Treasury BillsBNY-BVPDM15
Holdings [Line Items]
Percent of Net Asset Value	4.90%
C000004007 \| Top10HoldingUnited Kingdom GiltBNY-BVP9978
Holdings [Line Items]
Percent of Net Asset Value	3.70%
C000004007 \| Top10HoldingRepublic of SingaporeBNY-BD1RC15
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000004007 \| Top10HoldingItaly Buoni Poliennali Del TesoroBNY-BSNNZ95
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000004007 \| Top10HoldingRepublic of IndonesiaBNY-BL53JN6
Holdings [Line Items]
Percent of Net Asset Value	2.60%
C000004007 \| Top10HoldingDeutsche BundesrepublikBNY-BLM7VX5
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000004007 \| Top10HoldingGovernment of MalaysiaBNY-BYZ0DL4
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000004007 \| Top10HoldingGovernment of CanadaBNY-BPP4M94
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000004007 \| Investment TypeOther Holdings Grouping
Holdings [Line Items]
Percent of Net Asset Value	45.90%
C000004007 \| United States
Holdings [Line Items]
Percent of Net Asset Value	12.50%
C000004007 \| Japan
Holdings [Line Items]
Percent of Net Asset Value	12.00%
C000004007 \| United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	6.00%
C000004007 \| Canada
Holdings [Line Items]
Percent of Net Asset Value	5.80%
C000004007 \| China
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000004007 \| Germany
Holdings [Line Items]
Percent of Net Asset Value	3.50%
C000004007 \| Italy
Holdings [Line Items]
Percent of Net Asset Value	3.30%
C000004007 \| France
Holdings [Line Items]
Percent of Net Asset Value	3.20%
C000004007 \| Singapore
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000004008 \| Top10HoldingGovernment of JapanBNY-BR51DF2
Holdings [Line Items]
Percent of Net Asset Value	7.10%
C000004008 \| Top10HoldingPeople's Republic of ChinaBNY-BVBHMF5
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000004008 \| Top10HoldingGovernment of Japan Treasury BillsBNY-BVPDM15
Holdings [Line Items]
Percent of Net Asset Value	4.90%
C000004008 \| Top10HoldingUnited Kingdom GiltBNY-BVP9978
Holdings [Line Items]
Percent of Net Asset Value	3.70%
C000004008 \| Top10HoldingRepublic of SingaporeBNY-BD1RC15
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000004008 \| Top10HoldingItaly Buoni Poliennali Del TesoroBNY-BSNNZ95
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000004008 \| Top10HoldingRepublic of IndonesiaBNY-BL53JN6
Holdings [Line Items]
Percent of Net Asset Value	2.60%
C000004008 \| Top10HoldingDeutsche BundesrepublikBNY-BLM7VX5
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000004008 \| Top10HoldingGovernment of MalaysiaBNY-BYZ0DL4
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000004008 \| Top10HoldingGovernment of CanadaBNY-BPP4M94
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000004008 \| Investment TypeOther Holdings Grouping
Holdings [Line Items]
Percent of Net Asset Value	45.90%
C000004008 \| United States
Holdings [Line Items]
Percent of Net Asset Value	12.50%
C000004008 \| Japan
Holdings [Line Items]
Percent of Net Asset Value	12.00%
C000004008 \| United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	6.00%
C000004008 \| Canada
Holdings [Line Items]
Percent of Net Asset Value	5.80%
C000004008 \| China
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000004008 \| Germany
Holdings [Line Items]
Percent of Net Asset Value	3.50%
C000004008 \| Italy
Holdings [Line Items]
Percent of Net Asset Value	3.30%
C000004008 \| France
Holdings [Line Items]
Percent of Net Asset Value	3.20%
C000004008 \| Singapore
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000159126 \| Top10HoldingGovernment of JapanBNY-BR51DF2
Holdings [Line Items]
Percent of Net Asset Value	7.10%
C000159126 \| Top10HoldingPeople's Republic of ChinaBNY-BVBHMF5
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000159126 \| Top10HoldingGovernment of Japan Treasury BillsBNY-BVPDM15
Holdings [Line Items]
Percent of Net Asset Value	4.90%
C000159126 \| Top10HoldingUnited Kingdom GiltBNY-BVP9978
Holdings [Line Items]
Percent of Net Asset Value	3.70%
C000159126 \| Top10HoldingRepublic of SingaporeBNY-BD1RC15
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000159126 \| Top10HoldingItaly Buoni Poliennali Del TesoroBNY-BSNNZ95
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000159126 \| Top10HoldingRepublic of IndonesiaBNY-BL53JN6
Holdings [Line Items]
Percent of Net Asset Value	2.60%
C000159126 \| Top10HoldingDeutsche BundesrepublikBNY-BLM7VX5
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000159126 \| Top10HoldingGovernment of MalaysiaBNY-BYZ0DL4
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000159126 \| Top10HoldingGovernment of CanadaBNY-BPP4M94
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000159126 \| Investment TypeOther Holdings Grouping
Holdings [Line Items]
Percent of Net Asset Value	45.90%
C000159126 \| United States
Holdings [Line Items]
Percent of Net Asset Value	12.50%
C000159126 \| Japan
Holdings [Line Items]
Percent of Net Asset Value	12.00%
C000159126 \| United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	6.00%
C000159126 \| Canada
Holdings [Line Items]
Percent of Net Asset Value	5.80%
C000159126 \| China
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000159126 \| Germany
Holdings [Line Items]
Percent of Net Asset Value	3.50%
C000159126 \| Italy
Holdings [Line Items]
Percent of Net Asset Value	3.30%
C000159126 \| France
Holdings [Line Items]
Percent of Net Asset Value	3.20%
C000159126 \| Singapore
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000219335 \| Top10HoldingGovernment of JapanBNY-BR51DF2
Holdings [Line Items]
Percent of Net Asset Value	7.10%
C000219335 \| Top10HoldingPeople's Republic of ChinaBNY-BVBHMF5
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000219335 \| Top10HoldingGovernment of Japan Treasury BillsBNY-BVPDM15
Holdings [Line Items]
Percent of Net Asset Value	4.90%
C000219335 \| Top10HoldingUnited Kingdom GiltBNY-BVP9978
Holdings [Line Items]
Percent of Net Asset Value	3.70%
C000219335 \| Top10HoldingRepublic of SingaporeBNY-BD1RC15
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000219335 \| Top10HoldingItaly Buoni Poliennali Del TesoroBNY-BSNNZ95
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000219335 \| Top10HoldingRepublic of IndonesiaBNY-BL53JN6
Holdings [Line Items]
Percent of Net Asset Value	2.60%
C000219335 \| Top10HoldingDeutsche BundesrepublikBNY-BLM7VX5
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000219335 \| Top10HoldingGovernment of MalaysiaBNY-BYZ0DL4
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000219335 \| Top10HoldingGovernment of CanadaBNY-BPP4M94
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000219335 \| Investment TypeOther Holdings Grouping
Holdings [Line Items]
Percent of Net Asset Value	45.90%
C000219335 \| United States
Holdings [Line Items]
Percent of Net Asset Value	12.50%
C000219335 \| Japan
Holdings [Line Items]
Percent of Net Asset Value	12.00%
C000219335 \| United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	6.00%
C000219335 \| Canada
Holdings [Line Items]
Percent of Net Asset Value	5.80%
C000219335 \| China
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000219335 \| Germany
Holdings [Line Items]
Percent of Net Asset Value	3.50%
C000219335 \| Italy
Holdings [Line Items]
Percent of Net Asset Value	3.30%
C000219335 \| France
Holdings [Line Items]
Percent of Net Asset Value	3.20%
C000219335 \| Singapore
Holdings [Line Items]
Percent of Net Asset Value	2.80%

Shareholder Report, Holdings (Details)

Jun. 30, 2026