Securities Available for Sale - Amortized costs and fair values of debt securities available for sale (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 501,478	$ 443,249
Gross Unrealized Gains	10,964	6,967
Gross Unrealized Losses	582	914
Fair Value	511,860	449,302
U.S. government agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	64,180	16,516
Gross Unrealized Gains	288	4
Gross Unrealized Losses	216	60
Fair Value	64,252	16,460
State, county and municipals
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	155,700	155,501
Gross Unrealized Gains	1,661	1,049
Gross Unrealized Losses	25	157
Fair Value	157,336	156,393
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	203,575	193,223
Gross Unrealized Gains	6,499	2,492
Gross Unrealized Losses	121	697
Fair Value	209,953	195,018
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	78,023	78,009
Gross Unrealized Gains	2,516	3,422
Gross Unrealized Losses	220	0
Fair Value	$ 80,319	$ 81,431

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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