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 (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	36,679				36,679
Other comprehensive income (loss), net of tax	(18,191)					(18,191)
Cash dividends on common stock	(8,912)				(8,912)
Reclassification adjustment under ASU 2018-02	0				626	(626)
Share-based compensation (in shares)			93,076
Share-based compensation	875		$ 12	863
Stock issued under employee benefit plans (in shares)			4,363
Stock issued under employee benefit plans	159		$ 1	158
Stock issued under dividend reinvestment and stock purchase plan (in shares)			5,614
Stock issued under dividend reinvestment and stock purchase plan	250		$ 1	249
Stock options exercised (in shares)			23,557
Stock options exercised	535		$ 3	532
Stock redeemed (in shares)			(41,752)
Stock redeemed	(1,785)		$ (7)	(1,778)
Ending balance (in shares) at Mar. 31, 2018		125	49,243,096
Ending balance at Mar. 31, 2018	1,313,073	$ 125	$ 6,155	834,894	493,624	(21,725)
Beginning balance (in shares) at Dec. 31, 2018		125	49,349,800
Beginning balance at Dec. 31, 2018	1,408,260	$ 125	$ 6,169	840,052	583,336	(21,422)
Comprehensive income:
Net income	38,817				38,817
Other comprehensive income (loss), net of tax	19,827					19,827
Cash dividends on common stock	(10,933)				(10,933)
Reclassification adjustment under ASU 2018-02						(626)
Share-based compensation (in shares)			103,660
Share-based compensation	981		$ 13	968
Stock issued under employee benefit plans (in shares)			5,339
Stock issued under employee benefit plans	174		$ 1	173
Stock issued under dividend reinvestment and stock purchase plan (in shares)			8,508
Stock issued under dividend reinvestment and stock purchase plan	$ 340		$ 1	339
Stock options exercised (in shares)	3,700		3,700
Stock options exercised	$ 40		$ 0	40
Stock redeemed (in shares)			(42,539)
Stock redeemed	(1,658)		$ (5)	(1,653)
Ending balance (in shares) at Mar. 31, 2019		125	49,428,468
Ending balance at Mar. 31, 2019	$ 1,455,848	$ 125	$ 6,179	$ 839,919	$ 611,220	$ (1,595)