Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative adjustment for adoption of ASU 2016-01				$ (2,043)
January 1, 2018, as adjusted				(4,392)
Balance at beginning of period at Dec. 31, 2017	$ 583,122	$ 512,734	$ 72,737	(2,349)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	47,851		47,851
Other comprehensive loss, net of tax	(9,099)			(9,099)
Stock based compensation	1,930	1,930
Exercise of stock options	307	307
Retirement of restricted stock	(759)	(759)
Cash dividends on common stock of $0.33 per share	(15,797)		(15,797)
Balance at end of period at Sep. 30, 2018	607,555	514,212	106,834	(13,491)
Balance at beginning of period at Jun. 30, 2018	597,864	513,756	95,586	(11,478)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	16,758		16,758
Other comprehensive loss, net of tax	(2,013)			(2,013)
Stock based compensation	471	471
Retirement of restricted stock	(15)	(15)
Cash dividends on common stock of $0.33 per share	(5,510)		(5,510)
Balance at end of period at Sep. 30, 2018	607,555	514,212	106,834	(13,491)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative adjustment for adoption of ASU 2016-01				0
January 1, 2018, as adjusted				(7,838)
Balance at beginning of period at Dec. 31, 2018	623,739	514,703	116,874	(7,838)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	51,957		51,957
Other comprehensive loss, net of tax	11,048			11,048
Stock based compensation	1,822	1,822
Exercise of stock options	307	307
Retirement of restricted stock	(654)	(654)
Cash dividends on common stock of $0.33 per share	(18,557)		(18,557)
Issuance of stock for Highlands acquisition	43,417	43,417
Balance at end of period at Sep. 30, 2019	713,204	559,595	150,399	3,210
Balance at beginning of period at Jun. 30, 2019	698,463	558,768	137,887	1,808
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	18,874		18,874
Other comprehensive loss, net of tax	1,402			1,402
Stock based compensation	558	558
Exercise of stock options	307	307
Retirement of restricted stock	(38)	(38)
Cash dividends on common stock of $0.33 per share	(6,362)		(6,362)
Balance at end of period at Sep. 30, 2019	$ 713,204	$ 559,595	$ 150,399	$ 3,210

Restricted stock award retirements.

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Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Value of stock issued pursuant to acquisitions during the period.

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Value of stock issued as a result of the exercise of stock options.

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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Amount of stockholders' equity including the portion attributable to noncontrolling interests, after the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

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