Shareholder Report, Holdings (Details)	Jun. 30, 2026
C000017180 \| NVIDIA Corp.
Holdings [Line Items]
Percent of Net Asset Value	13.90%
C000017180 \| Alphabet, Inc.
Holdings [Line Items]
Percent of Net Asset Value	11.00%
C000017180 \| Apple, Inc.
Holdings [Line Items]
Percent of Net Asset Value	6.90%
C000017180 \| Broadcom, Inc.
Holdings [Line Items]
Percent of Net Asset Value	5.30%
C000017180 \| Microsoft Corp.
Holdings [Line Items]
Percent of Net Asset Value	4.60%
C000017180 \| Applied Materials, Inc.
Holdings [Line Items]
Percent of Net Asset Value	2.70%
C000017180 \| Meta Platforms, Inc.
Holdings [Line Items]
Percent of Net Asset Value	2.40%
C000017180 \| Marvell Technology, Inc.
Holdings [Line Items]
Percent of Net Asset Value	2.20%
C000017180 \| Eli Lilly & Co.
Holdings [Line Items]
Percent of Net Asset Value	2.20%
C000017180 \| Mastercard, Inc.
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017180 \| SectorInformation Technology
Holdings [Line Items]
Percent of Net Asset Value	49.00%
C000017180 \| SectorCommunication Services
Holdings [Line Items]
Percent of Net Asset Value	19.00%
C000017180 \| SectorIndustrials
Holdings [Line Items]
Percent of Net Asset Value	14.00%
C000017180 \| SectorConsumer Discretionary
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000017180 \| SectorHealth Care
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000017180 \| SectorFinancials
Holdings [Line Items]
Percent of Net Asset Value	4.00%
C000017180 \| SectorReal Estate
Holdings [Line Items]
Percent of Net Asset Value	1.00%
C000017180 \| SectorConsumer Staples
Holdings [Line Items]
Percent of Net Asset Value	1.00%
C000017180 \| SectorMaterials
Holdings [Line Items]
Percent of Net Asset Value	1.00%
C000017180 \| AssetCommon Stocks
Holdings [Line Items]
Percent of Net Asset Value	98.00%
C000017180 \| AssetCash Equivalents
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017180 \| Asset Other Net Line
Holdings [Line Items]
Percent of Net Asset Value	0.00%
C000017184 \| NVIDIA Corp.
Holdings [Line Items]
Percent of Net Asset Value	6.40%
C000017184 \| Alphabet, Inc.
Holdings [Line Items]
Percent of Net Asset Value	5.90%
C000017184 \| Apple, Inc.
Holdings [Line Items]
Percent of Net Asset Value	8.60%
C000017184 \| Broadcom, Inc.
Holdings [Line Items]
Percent of Net Asset Value	2.20%
C000017184 \| Microsoft Corp.
Holdings [Line Items]
Percent of Net Asset Value	5.90%
C000017184 \| Micron Technology, Inc.
Holdings [Line Items]
Percent of Net Asset Value	4.60%
C000017184 \| Amazon.com, Inc.
Holdings [Line Items]
Percent of Net Asset Value	4.40%
C000017184 \| Advanced Micro Devices, Inc.
Holdings [Line Items]
Percent of Net Asset Value	3.40%
C000017184 \| JPMorgan Chase & Co.
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000017184 \| AbbVie, Inc.
Holdings [Line Items]
Percent of Net Asset Value	2.10%
C000017184 \| SectorInformation Technology
Holdings [Line Items]
Percent of Net Asset Value	38.00%
C000017184 \| SectorCommunication Services
Holdings [Line Items]
Percent of Net Asset Value	9.00%
C000017184 \| SectorIndustrials
Holdings [Line Items]
Percent of Net Asset Value	9.00%
C000017184 \| SectorConsumer Discretionary
Holdings [Line Items]
Percent of Net Asset Value	10.00%
C000017184 \| SectorHealth Care
Holdings [Line Items]
Percent of Net Asset Value	8.00%
C000017184 \| SectorFinancials
Holdings [Line Items]
Percent of Net Asset Value	12.00%
C000017184 \| SectorReal Estate
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017184 \| SectorConsumer Staples
Holdings [Line Items]
Percent of Net Asset Value	4.00%
C000017184 \| SectorMaterials
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017184 \| SectorEnergy
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000017184 \| SectorUtilities
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017184 \| AssetCommon Stocks
Holdings [Line Items]
Percent of Net Asset Value	99.00%
C000017184 \| AssetCash Equivalents
Holdings [Line Items]
Percent of Net Asset Value	1.00%
C000017184 \| Asset Other Net Line
Holdings [Line Items]
Percent of Net Asset Value	0.00%
C000017188 \| BHP Group Ltd.
Holdings [Line Items]
Percent of Net Asset Value	3.90%
C000017188 \| UniCredit SpA
Holdings [Line Items]
Percent of Net Asset Value	3.30%
C000017188 \| Sanofi SA
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000017188 \| Banco Santander SA
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000017188 \| BNP Paribas SA
Holdings [Line Items]
Percent of Net Asset Value	2.80%
C000017188 \| DCC PLC
Holdings [Line Items]
Percent of Net Asset Value	2.70%
C000017188 \| Credit Agricole SA
Holdings [Line Items]
Percent of Net Asset Value	2.50%
C000017188 \| Ono Pharmaceutical Co., Ltd.
Holdings [Line Items]
Percent of Net Asset Value	2.40%
C000017188 \| Central Japan Railway Co.
Holdings [Line Items]
Percent of Net Asset Value	2.40%
C000017188 \| Imperial Brands PLC
Holdings [Line Items]
Percent of Net Asset Value	2.30%
C000017188 \| Country Other Line
Holdings [Line Items]
Percent of Net Asset Value	10.00%
C000017188 \| SectorInformation Technology
Holdings [Line Items]
Percent of Net Asset Value	4.00%
C000017188 \| SectorCommunication Services
Holdings [Line Items]
Percent of Net Asset Value	4.00%
C000017188 \| SectorIndustrials
Holdings [Line Items]
Percent of Net Asset Value	10.00%
C000017188 \| SectorConsumer Discretionary
Holdings [Line Items]
Percent of Net Asset Value	6.00%
C000017188 \| SectorHealth Care
Holdings [Line Items]
Percent of Net Asset Value	17.00%
C000017188 \| SectorFinancials
Holdings [Line Items]
Percent of Net Asset Value	26.00%
C000017188 \| SectorConsumer Staples
Holdings [Line Items]
Percent of Net Asset Value	12.00%
C000017188 \| SectorMaterials
Holdings [Line Items]
Percent of Net Asset Value	9.00%
C000017188 \| SectorEnergy
Holdings [Line Items]
Percent of Net Asset Value	7.00%
C000017188 \| SectorUtilities
Holdings [Line Items]
Percent of Net Asset Value	4.00%
C000017188 \| Japan
Holdings [Line Items]
Percent of Net Asset Value	24.00%
C000017188 \| United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	18.00%
C000017188 \| France
Holdings [Line Items]
Percent of Net Asset Value	14.00%
C000017188 \| Australia
Holdings [Line Items]
Percent of Net Asset Value	6.00%
C000017188 \| Italy
Holdings [Line Items]
Percent of Net Asset Value	6.00%
C000017188 \| Singapore
Holdings [Line Items]
Percent of Net Asset Value	6.00%
C000017188 \| Spain
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000017188 \| Germany
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000017188 \| Switzerland
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000017188 \| Ireland
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000017188 \| AssetCommon Stocks
Holdings [Line Items]
Percent of Net Asset Value	97.00%
C000017188 \| AssetCash Equivalents
Holdings [Line Items]
Percent of Net Asset Value	1.00%
C000017188 \| Asset Other Net Line
Holdings [Line Items]
Percent of Net Asset Value	0.00%
C000017188 \| AssetPreferred Stocks
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017182 \| Benchmark Electronics, Inc.
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017182 \| Madison Square Garden Sports Corp.
Holdings [Line Items]
Percent of Net Asset Value	1.90%
C000017182 \| Affiliated Managers Group, Inc.
Holdings [Line Items]
Percent of Net Asset Value	1.80%
C000017182 \| Lumentum Holdings, Inc.
Holdings [Line Items]
Percent of Net Asset Value	1.80%
C000017182 \| TechnipFMC PLC
Holdings [Line Items]
Percent of Net Asset Value	1.70%
C000017182 \| Ducommun, Inc.
Holdings [Line Items]
Percent of Net Asset Value	1.70%
C000017182 \| Adeia, Inc.
Holdings [Line Items]
Percent of Net Asset Value	1.70%
C000017182 \| Bridgebio Pharma, Inc.
Holdings [Line Items]
Percent of Net Asset Value	1.60%
C000017182 \| Popular, Inc.
Holdings [Line Items]
Percent of Net Asset Value	1.40%
C000017182 \| ACM Research, Inc.
Holdings [Line Items]
Percent of Net Asset Value	1.40%
C000017182 \| Country Other Line
Holdings [Line Items]
Percent of Net Asset Value	6.00%
C000017182 \| South Korea
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017182 \| SectorInformation Technology
Holdings [Line Items]
Percent of Net Asset Value	17.00%
C000017182 \| SectorCommunication Services
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000017182 \| SectorIndustrials
Holdings [Line Items]
Percent of Net Asset Value	20.00%
C000017182 \| SectorConsumer Discretionary
Holdings [Line Items]
Percent of Net Asset Value	10.00%
C000017182 \| SectorHealth Care
Holdings [Line Items]
Percent of Net Asset Value	10.00%
C000017182 \| SectorFinancials
Holdings [Line Items]
Percent of Net Asset Value	14.00%
C000017182 \| SectorReal Estate
Holdings [Line Items]
Percent of Net Asset Value	6.00%
C000017182 \| SectorConsumer Staples
Holdings [Line Items]
Percent of Net Asset Value	4.00%
C000017182 \| SectorMaterials
Holdings [Line Items]
Percent of Net Asset Value	7.00%
C000017182 \| SectorEnergy
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000017182 \| SectorUtilities
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000017182 \| Japan
Holdings [Line Items]
Percent of Net Asset Value	6.00%
C000017182 \| United Kingdom
Holdings [Line Items]
Percent of Net Asset Value	5.00%
C000017182 \| France
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017182 \| Australia
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017182 \| Germany
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017182 \| Switzerland
Holdings [Line Items]
Percent of Net Asset Value	2.00%
C000017182 \| United States
Holdings [Line Items]
Percent of Net Asset Value	67.00%
C000017182 \| Canada
Holdings [Line Items]
Percent of Net Asset Value	3.00%
C000017182 \| Puerto Rico
Holdings [Line Items]
Percent of Net Asset Value	1.00%
C000017182 \| AssetCommon Stocks
Holdings [Line Items]
Percent of Net Asset Value	99.00%
C000017182 \| AssetCash Equivalents
Holdings [Line Items]
Percent of Net Asset Value	1.00%
C000017182 \| Asset Other Net Line
Holdings [Line Items]
Percent of Net Asset Value	0.00%