Consolidated Statement of Stockholders' Equity (Unaudited) (Parentheticals) - $ / shares	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Statement of Stockholders' Equity [Abstract]
Dividends on common stock, per share (in dollars per share)	$ 0.33	$ 0.33	$ 0.31	$ 3.31	$ 0.31	$ 0.28