Stockholders' Equity and Restrictions - Changes in Stock (Details) - shares	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Class of Stock [Line Items]
Treasury Stock, Balance at beginning of year	4,937,000	4,138,000
Treasury Stock, Balance at end of period	5,262,000	4,753,000
Common Stock Class A [Member]
Class of Stock [Line Items]
Common Stock, Balance at beginning of year	53,758,000	53,170,000
Treasury Stock, Balance at beginning of year	3,935,581
Stock issued, new issues	0	22,000
Stock issued for compensation	122,000	90,000
Acquisition of Class A shares	0	0
Treasury Stock, Shares, Acquired	325,000	615,000
Common Stock, Balance at end of period	53,880,000	53,757,000
Treasury Stock, Balance at end of period	4,261,005
Common Stock Class A [Member] | Stock Investment Plan
Class of Stock [Line Items]
Stock issued, new issues	0	475,000
Common Stock Class B [Member]
Class of Stock [Line Items]
Common Stock, Balance at beginning of year	1,002,000	1,002,000
Treasury Stock, Balance at beginning of year	1,001,714
Stock issued, new issues	0	0
Stock issued for compensation	0	0
Acquisition of Class A shares	0	0
Common Stock, Balance at end of period	1,002,000	1,002,000
Treasury Stock, Balance at end of period	1,001,714
Common Stock Class B [Member] | Stock Investment Plan
Class of Stock [Line Items]
Stock issued, new issues	0	0
Treasury Stock, Common [Member]
Class of Stock [Line Items]
Stock issued, new issues	0	0
Stock issued for compensation	0	0
Treasury Stock, Common [Member] | Stock Investment Plan
Class of Stock [Line Items]
Stock issued, new issues	0	0