Securities - Additional Information (Details) - USD ($)	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Schedule Of Marketable Securities [Line Items]
Debt Securities, Available-for-sale, Restricted	$ 57,200,000		$ 55,800,000
Fair Value of Investment in debt securities	998,000		$ 1,000,000
Percentage of fair value of investment in debt			1.00%
Proceeds from sale of available-for-sale securities	$ 0	$ 8,070,000
U.S. government agencies
Schedule Of Marketable Securities [Line Items]
Proceeds from sale of available-for-sale securities		8,000,000
Debt Securities, Available-for-sale, Realized Gain (Loss)		$ 69,000

Percentage of total investment portfolio, fair value.

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Schedule Of Marketable Securities [Line Items]

+ References

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Amount of realized gain (loss) on 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/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563

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Amount of restricted 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 860
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-Section 50
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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
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Amount of cash inflow from sale 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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
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