Consolidated Statements of Changes in Stockholders Equity (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Retained earnings	Accumulated other comprehensive income
Beginning Balance at Dec. 31, 2015	$ 950,493	$ 311,720	$ 638,367	$ 406
Comprehensive income:
Net income	45,678	0	45,678	0
Other comprehensive income, net of tax	10,016	0	0	10,016
Common stock transactions:
Common shares purchased and retired 998,135 and 789,743 in 2016 and 2015, respectively	(26,042)	(26,042)	0	0
Stock Issued During Period, 16,085 and 21,414 in 2016 and 2015, respectively	0	0	0	0
Non-vested common shares issued 189,624 and 169,577 in 2016 and 2015 respectively	0	0	0	0
25,984 and 3,484 non-vested common shares forfeited in 2016 and 2015 respectively	0	0	0	0
270,183 and 158,828 stock options exercised, net of 94,902 and 58,996 shares tendered in payment of option price and income tax withholding amounts in 2016 and 2015 respectively	1,684	1,684	0	0
Tax benefit of stock-based compensation	619	619	0	0
Stock-based compensation expense	2,385	2,385	0	0
Cash dividends declared:
Common ($0.66 per share) in 2016 and ($0.60 per share) in 2015	(19,708)	0	(19,708)	0
Ending Balance at Jun. 30, 2016	965,125	290,366	664,337	10,422
Beginning Balance at Dec. 31, 2016	982,593	296,071	694,650	(8,128)
Comprehensive income:
Net income	44,994	0	44,994	0
Other comprehensive income, net of tax	10,124	0	0	10,124
Common stock transactions:
Common shares purchased and retired 998,135 and 789,743 in 2016 and 2015, respectively	(891)	(891)	0	0
Stock Issued During Period, 16,085 and 21,414 in 2016 and 2015, respectively	385,969	385,969	0	0
Non-vested common shares issued 189,624 and 169,577 in 2016 and 2015 respectively	0	0	0	0
25,984 and 3,484 non-vested common shares forfeited in 2016 and 2015 respectively	0	0	0	0
270,183 and 158,828 stock options exercised, net of 94,902 and 58,996 shares tendered in payment of option price and income tax withholding amounts in 2016 and 2015 respectively	1,672	1,672	0	0
Stock-based compensation expense	2,468	2,468	0	0
Cash dividends declared:
Common ($0.66 per share) in 2016 and ($0.60 per share) in 2015	(21,551)	0	(21,551)	0
Ending Balance at Jun. 30, 2017	$ 1,405,378	$ 685,289	$ 718,093	$ 1,996