Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Statement of Stockholders' Equity [Abstract]
Stock option exercises (shares)	908,921	227,851
Treasury stock, shares, acquired	0	1,095,308
Cash dividends declared on preferred stock, per share	$ 1.01	$ 1.01
Cash dividends declared on common stock, per share	$ 1.61	$ 1.57