Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Stockholders' Equity [Abstract]
Stock option exercises/stock unit conversions (shares)	53,035	110,489	153,900	428,599
Treasury stock, shares, acquired	496,307	601	501,658	601
Approximate cash dividends declared on preferred stock, per share	$ 0.33	$ 0.33	$ 0.67	$ 0.67
Cash dividends declared on common stock, per share	$ 0.71	$ 0.67	$ 1.38	$ 1.24