Note 8 - Stockholders' Equity (Details Textual) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Preferred Stock, Shares Authorized (in shares)	50,000,000				50,000,000	50,000,000
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.01				$ 0.01	$ 0.01
Preferred Stock, Shares Outstanding, Ending Balance (in shares)	0				0	0
Common Stock, Shares Authorized (in shares)	450,000,000				450,000,000	450,000,000
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.01				$ 0.01	$ 0.01
Common Stock, Shares, Issued, Total (in shares)	155,900,251				155,900,251
Common Stock, Shares, Outstanding, Ending Balance (in shares)	144,238,660				144,238,660	144,515,658
Treasury Stock, Shares, Ending Balance (in shares)	11,661,591				11,661,591	10,442,582
Common Stock, Dividends, Per Share, Declared (in dollars per share)	$ 0.10	$ 0.10	$ 0.10	$ 0.10	$ 0.40	$ 0.10	$ 0.40
Payments of Ordinary Dividends, Common Stock					$ 58	$ 15	$ 58
Treasury Stock, Value, Acquired, Cost Method		$ 23			23		$ 25
Treasury Stock, Shares, Acquired (in shares)		1,000,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 127				$ 127