Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)
Balance at beginning of period at Dec. 31, 2016	$ 550,044	$ 510,861	$ 38,590	$ 593
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	52,580		52,580
Other comprehensive income (loss), net of tax	(2,522)			(2,522)
Adjustment related to implementation of ASU 2018-02	0		420	(420)
Stock based compensation	2,325	2,325
Retirement of restricted stock	(773)	(773)
Exercise of stock options, net of excess tax benefits	321	321
Cash dividends, common stock	(18,853)		(18,853)
Balance at end of period at Dec. 31, 2017	583,122	512,734	72,737	(2,349)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	63,401		63,401
Other comprehensive income (loss), net of tax	(3,446)			(3,446)
Adjustment related to implementation of ASU 2018-02				(2,043)
Stock based compensation	2,425	2,425
Retirement of restricted stock	(763)	(763)
Exercise of stock options, net of excess tax benefits	307	307
Cash dividends, common stock	(21,307)		(21,307)
Balance at end of period at Dec. 31, 2018	623,739	514,703	116,874	(7,838)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	70,672		70,672
Other comprehensive income (loss), net of tax	10,086			10,086
Stock based compensation	2,545	2,545
Issuance of stock for Highlands acquisition	43,417	43,417
Retirement of restricted stock	(715)	(715)
Exercise of stock options, net of excess tax benefits	313	313
Cash dividends, common stock	(24,919)		(24,919)
Balance at end of period at Dec. 31, 2019	$ 725,263	$ 560,263	$ 162,752	$ 2,248