Stockholders' Equity - Additional Information (Detail) - shares	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Stock Option Plan [Member]
Class of Stock [Line Items]
Number of outstanding options	0	0
Minimum [Member]
Class of Stock [Line Items]
Class A common stock entitled dividend per share percent in comparison to Class B common stock	200.00%
Minimum [Member] \| Stock Option Plan [Member]
Class of Stock [Line Items]
Share based compensation of option price based on fair value	85.00%
Maximum [Member] \| Stock Option Plan [Member]
Class of Stock [Line Items]
Share based compensation number of share authorized	150,000
Stock option exercisable period	10 years

Dividends entitlement percentage as percentage of class B common stock dividends.

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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

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Paragraph 2
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- Definition

Number of options outstanding, including both vested and non-vested options.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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- Definition

Purchase price of common stock expressed as a percentage of its fair value.

+ References

No definition available.

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