Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parentheticals) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Retained Earnings [Member]
Dividends and dividend equivalents declared per share (in dollars per share)	$ 0.40	$ 0.30	$ 1.20	$ 0.90
Dividends and dividend equivalents declared per share (in dollars per share)	$ 0.40	$ 0.30	$ 1.20	$ 0.90