Shareholder Report, Holdings (Details) - C000004917 [Member]	Dec. 31, 2024
Microsoft Corp [Member]
Holdings [Line Items]
Percent of Net Asset Value	31.60%	[1]
Berkshire Hathaway Inc Class B [Member]
Holdings [Line Items]
Percent of Net Asset Value	12.90%	[1]
JPMorgan Chase And Co [Member]
Holdings [Line Items]
Percent of Net Asset Value	8.30%	[1]
General Dynamics Corp [Member]
Holdings [Line Items]
Percent of Net Asset Value	7.80%	[1]
American Express Co [Member]
Holdings [Line Items]
Percent of Net Asset Value	6.90%	[1]
Visa Inc Class A [Member]
Holdings [Line Items]
Percent of Net Asset Value	4.80%	[1]
AstraZeneca PLC ADR [Member]
Holdings [Line Items]
Percent of Net Asset Value	3.20%	[1]
Johnson And Johnson [Member]
Holdings [Line Items]
Percent of Net Asset Value	3.00%	[1]
Walmart Inc [Member]
Holdings [Line Items]
Percent of Net Asset Value	2.80%	[1]
Merck And Co Inc [Member]
Holdings [Line Items]
Percent of Net Asset Value	2.60%	[1]
Energy Sector [Member]
Holdings [Line Items]
Percent of Net Asset Value	3.60%	[2]
Financial Services Sector [Member]
Holdings [Line Items]
Percent of Net Asset Value	32.90%	[2]
Healthcare Sector [Member]
Holdings [Line Items]
Percent of Net Asset Value	12.90%	[2]
Consumer Staples Sector [Member]
Holdings [Line Items]
Percent of Net Asset Value	10.30%	[2]
Industrial Sector [Member]
Holdings [Line Items]
Percent of Net Asset Value	7.80%	[2]
Information Technology Sector [Member]
Holdings [Line Items]
Percent of Net Asset Value	32.60%	[2]
Short-Term Investments [Member]
Holdings [Line Items]
Percent of Net Asset Value	0.20%	[2]
Liabilities in Excess of Other Assets [Member]
Holdings [Line Items]
Percent of Net Asset Value	(0.30%)	[2]

[1] Excludes short-term securities.

[2] For purposes of this report, sector sub-classifications may differ from those utilized by the Fund for compliance purposes.