Consolidated Statements of Changes in Stockholders' Equity (Parentheticals) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock issued to directors, shares (in shares)	391,000	253,000	162,000
Common stock issued for cash, shares (in shares)		21,410,000	2,565,000
Stock issued for 401(k) match, shares (in shares)	1,584,000	1,882,000	1,068,000
Common stock and warrants issued for purchase of another company, shares (in shares)			75,276,000
Common stock dividends declared, per common share (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock issued for employee incentive compensation,shares (in shares)	2,800,000	3,597,000	1,237,000
Common stock issued to pension plans, shares (in shares)	2,869,000	2,384,000	2,736,000
Restricted stock unit distributions, shares (in shares)	1,702,000	1,164,000	1,079,000
Common stock issued for prepayment of debt, sahres (in shares)		10,665,000
Treasury shares issued to charitable foundation, shares (in shares)	650,000