CONSOLIDATED CONDENSED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Preferred	Common Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income
Beginning balance at Dec. 31, 2016						$ (13,581)
Comprehensive income:
Net income	$ 71,687
Other comprehensive loss, net of tax	7,223
Ending balance at Sep. 30, 2017						(6,358)
Beginning balance (in shares) at Dec. 31, 2017		125	49,158,238
Beginning balance at Dec. 31, 2017	1,303,463	$ 125	$ 6,145	$ 834,870	$ 465,231	(2,908)
Comprehensive income:
Net income	117,426				117,426
Other comprehensive loss, net of tax	(31,875)					(31,875)
Cash dividends on common stock ($.62 per share)	(30,732)				(30,732)
Reclassification adjustment under ASU 2018-02	0				626	(626)
Share-based compensation (in shares)			106,833
Share-based compensation	2,546		$ 13	2,533
Stock issued under employee benefit plans (in shares)			13,448
Stock issued under employee benefit plans	515		$ 2	513
Stock issued under dividend reinvestment and stock purchase plan (in shares)			18,761
Stock issued under dividend reinvestment and stock purchase plan	$ 879		$ 2	877
Stock options exercised (in shares)	51,243		51,243
Stock options exercised	$ 1,093		$ 6	1,087
Stock redeemed (in shares)			(43,981)
Stock redeemed	(1,889)		$ (5)	(1,884)
Ending balance (in shares) at Sep. 30, 2018		125	49,304,542
Ending balance at Sep. 30, 2018	$ 1,361,426	$ 125	$ 6,163	$ 837,996	$ 552,551	$ (35,409)