Consolidated Statements of Changes in Equity (Unaudited) (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash dividends per share common stock (in dollars per share)	$ 0.33	$ 0.30
Shares of common stock purchased (in shares)	9,392	49,785
Shares of common stock issued (in shares)	3,835,532	2,295,472
Series C Preferred Stock
Cash dividends per share preferred stock (in dollars per share)		$ 2.50
Series D Preferred Stock
Cash dividends per share preferred stock (in dollars per share)	$ 52.50	$ 35.00