Financial Instruments - Interest Rate Swaps - Additional Information (Details)	12 Months Ended
Dec. 31, 2020 USD ($) swap	Dec. 31, 2019 USD ($)
Interest rate swaps
Debt Securities, Available-for-sale [Line Items]
Fair value hedging instruments	$ 0	$ 0
Number of interest rate swaps terminated \| swap	1
Number of interest rate swaps outstanding \| swap	4
Interest rate swap, April 2025 expiration
Debt Securities, Available-for-sale [Line Items]
Interest rate swap, term of contract	5 years
Notional amount	$ 50,000,000.0
Interest rate swap, fixed interest rate	0.885%
Interest rate swap, October 2020 expiration
Debt Securities, Available-for-sale [Line Items]
Notional amount	$ 25,000,000.0
Interest rate swap, February 2021 expiration
Debt Securities, Available-for-sale [Line Items]
Notional amount	$ 10,000,000
Interest rate swap, fixed interest rate	1.12%
Interest rate swap, May 2022 expiration
Debt Securities, Available-for-sale [Line Items]
Notional amount	$ 20,000,000
Interest rate swap, fixed interest rate	1.77%
Interest rate swap, June 2023 expiration
Debt Securities, Available-for-sale [Line Items]
Notional amount	$ 15,000,000
Interest rate swap, fixed interest rate	2.64%

Derivative, Number of Instruments Terminated

No definition available.

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- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

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- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
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-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

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- Definition

Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Net fair value of all derivative instruments designated as fair value hedging instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=117331979&loc=d3e41228-113958

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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