Consolidated Statements of Changes in Stockholders Equity (Unaudited) (Parenthetical) - $ / shares	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Common stock
Common stock transactions:
Common shares purchased and retired	21,454	995,600
Common shares issued	11,267,676	16,085
Non-vested common shares issued	134,044	189,624
Non-vested common shares forfeited	16,712	21,397
Stock options exercised	155,537	186,430
Shares tendered in payment of option price and income tax withholding amounts	50,698	57,153
Retained earnings
Cash dividends declared:
Common (in dollars per share)	$ 0.48	$ 0.44