Aggregate dividends declared during the period for each share of common stock outstanding.

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Date the declared dividend will be paid, in YYYY-MM-DD format.

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Amount of stock repurchase plan authorized.

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Amount remaining of a stock repurchase plan authorized.

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Number of shares that have been repurchased during the period and are being held in treasury.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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Note 6 - Capital Stock (Details Textual) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended			6 Months Ended
	Jul. 21, 2021	Apr. 22, 2021	Jan. 21, 2021	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Jan. 22, 2020	Apr. 20, 2017
Stock Repurchase Program, Authorized Amount									$ 500,000	$ 500,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount				$ 416,000			$ 416,000
Treasury Stock, Shares, Acquired (in shares)				484,000			518,000
Treasury Stock, Value, Acquired, Cost Method				$ 81,341		$ (0)	$ 86,580	$ 75,193
Common Stock, Dividends, Per Share, Declared (in dollars per share)		$ 0.30	$ 0.28		$ 0.27
Dividends Payable, Date Declared		Apr. 22, 2021
Dividends Payable, Date to be Paid		May 21, 2021
Dividends Payable, Date of Record		May 07, 2021
Subsequent Event [Member]
Common Stock, Dividends, Per Share, Declared (in dollars per share)	$ 0.30
Dividends Payable, Date Declared	Jul. 21, 2021
Dividends Payable, Date to be Paid	Aug. 20, 2021
Dividends Payable, Date of Record	Aug. 06, 2021