Securities - Amortized Cost and Fair Value of Securities Available for Sale and Held to Maturity (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Amortized cost within one year	$ 44,227	$ 37,386
Amortized cost one to five years	41,322	41,230
Amortized cost for five to ten years	114,900	117,004
Amortized cost for after ten years	270,421	213,574
Total amortized cost	470,870	409,194
Total available for sale investment securities, Amortized Cost	880,136	822,089
Within one year, amortized cost	10,082	7,811
One to five years, amortized cost	51,401	56,037
Five to ten years, amortized cost	91,291	94,756
After ten years, amortized cost	30,704	32,163
Total amortized cost	183,478	190,767
Investment securities, held to maturity	199,467	207,899
Fair value within one year	44,107	37,321
Fair value for one to five years	41,175	41,293
Fair value for five to ten years	119,147	122,145
Fair value for after ten years	278,184	218,193
Total fair value	482,613	418,952
Investment securities, available for sale	900,476	834,776
Within one year, fair value	10,127	7,874
One to five years, fair value	52,364	57,048
five to ten years, fair value	95,026	98,480
After ten years, fair value	33,340	34,440
Total fair value	190,857	197,842
Fair Value	207,324	215,147
Federal agency collateralized mortgage obligations
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	253,977	267,272
Investment securities, held to maturity	3,693	4,560
Investment securities, available for sale	257,813	269,252
Fair Value	3,746	4,568
Federal agency mortgage-backed pools
Schedule of Available-for-sale Securities [Line Items]
Total available for sale investment securities, Amortized Cost	155,289	145,623
Investment securities, held to maturity	12,296	12,572
Investment securities, available for sale	160,050	146,572
Fair Value	$ 12,721	$ 12,737

Available for sale securities debt maturities rolling fair value.

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Held to maturity securities debt maturities amortized cost.

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Held To Maturity Securities Debt Maturities Fair Value Aggregate

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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
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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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), with single maturity date and allocated without single maturity date, maturing after rolling tenth fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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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), with single maturity date and allocated without single maturity date, maturing in next rolling fiscal year through fifth year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Amount of investment in debt security measured at amortized cost (held-to-maturity).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 45
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in second through fifth rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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-Name Accounting Standards Codification
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Amount of investment in debt security measured at amortized cost (held-to-maturity), with single maturity date and allocated without single maturity date, maturing in sixth through tenth rolling fiscal year following latest fiscal year. For interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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