Note 8 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Billions		12 Months Ended
	Apr. 06, 2017	Dec. 03, 2022	Nov. 27, 2021	Nov. 28, 2020	Dec. 31, 2022	Dec. 31, 2021	Nov. 30, 2019
Preferred Stock, Shares Authorized (in shares)		10,045,900			10,045,900	10,045,900
Common Stock, Shares Authorized (in shares)		160,000,000			160,000,000	160,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)		$ 1.00			$ 1.00	$ 1.00
Common Stock, Shares, Issued (in shares)		53,676,576	52,777,753
Stock Repurchased During Period, Shares (in shares)		0	0	0
Common Stock, Shares, Outstanding, Ending Balance (in shares)		53,676,576	52,777,753	51,906,663	53,676,576	52,777,753	51,241,190
The 2017 Share Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount	$ 0.3
Stock Repurchase Program, Period in Force (Year)	5 years
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 0.3