Aggregate dividends declared during the period for each share of common stock outstanding.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

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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.

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

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

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Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Stockholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares issued	12,380,657		12,380,657	12,451,157	12,443,057	12,435,557
Common stock, shares outstanding	12,380,657		12,380,657	12,451,157	12,443,057	12,435,557
Preferred stock, shares authorized	1,000		1,000	1,000
Treasury stock purchases			75,000	0	0
Purchase of common shares			75,000
Shares available for purchase	602,547		602,547
Common Stock Dividend declared by directors			$ 0.20	$ 0.10	$ 0.07
Class A Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares issued	12,451,157		12,451,157	12,451,157
Common stock, shares outstanding	12,380,657		12,380,657	12,380,657
Common stock, shares authorized	20,000,000		20,000,000	20,000,000
Purchase of common shares	25,000	50,000	75,000
Purchase of common shares value			$ 1.3
Class A Common Stock \| 2013 Director Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for award	136,450		136,450
Class A Common Stock \| Non-Employee \| 2013 Director Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock shares authorized to be issued under the plan			200,000