Consolidated Statement of Changes in Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Common stock
Common stock transactions:
Common shares purchased and retired	38,753	24,271
Common shares issued	0	3,848,929
Non-vested common shares issued	200,028	214,892
Non-vested common shares forfeited	5,385	43,079
stock options exercised	56,982	161,217
net of shares tendered	19,004	38,450
Retained earnings
Common stock transactions:
Common dividends (in dollars per share)	$ 0.31	$ 1.12