Stockholders' Equity - Summary of Company's Share Option Plans Activities (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020
Number of Shares
Share options outstanding at beginning of year (in shares)	8,000
Granted (in shares)	0
Exercised (in shares)	(1,000)
Forfeited/expired (in shares)	(7,000)
Share options outstanding at end of year (in shares)	0	8,000
Option, Exercise Price [Roll Forward]
Option price, beginning of period (usd per share)	$ 0	$ 5.21	$ 0
Option price, granted (in usd per share)	0
Option price, exercised (in usd per share)	5.21
Option price, forfeited/cancelled (in usd per share)	5.21
Option price, end of period (usd per share)	0	5.21
Weighted Average Exercise Price
Share options outstanding at beginning of year, weighted average exercise price (usd per share)	5.21
Granted, weighted average exercise price (usd per share)	0
Exercised, weighted average exercise price (usd per share)	5.21
Forfeited/expired, weighted average exercise price (usd per share)	5.21
Share options outstanding at end of year, weighted average exercise price (usd per share)	$ 0	$ 5.21
Shares options outstanding vested or expected to vest - weighted average contractual life	0 years
Share options outstanding at end of year			$ 0

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Share-based Payment Arrangement, Option, Granted During Period, Exercise Price

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Share-based Payment Arrangement, Option, Outstanding, Exercise Price

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- Definition

Weighted average price of options that were either forfeited or expired.

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- Definition

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Net number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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- Definition

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

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Weighted average remaining contractual term for fully vested and expected to vest options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of share options (or share units) exercised during the current period.

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