Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Stockholders' Equity [Abstract]
Stock option exercises/stock unit conversions (shares)	101,284	19,232	255,184	447,831
Treasury stock, shares, acquired	202,724	0	704,382	601
Approximate cash dividends declared on preferred stock, per share	$ 0.34	$ 0.34	$ 1.01	$ 1.01
Cash dividends declared on common stock, per share	$ 0.71	$ 0.67	$ 2.09	$ 1.91