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Share-Based Compensation - Summary Activity in shares Subjected to Options and Weighted Average Exercise Prices (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
BYB Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Beginning balance	1,598,872
Number of Shares, Granted			0	212,400	1,634,568
Number of Shares, Exercised	(127,997)	(148,748)	0
Number of Shares, Forfeited	(60,800)
Number of Shares, Ending balance	1,410,075	1,598,872
Number of Shares, Exercisable	1,390,075
Weighted Average Exercise Price, Beginning balance	$ 11.84
Weighted Average Exercise Price, Exercised	14.71
Weighted Average Exercise Price, Forfeited	16.25
Weighted Average Exercise Price, Ending balance	11.38	$ 11.84
Weighted Average Exercise Price, Exercisable	$ 11.31
Intrinsic Value, Outstanding	$ 11,542	$ 7,713
Intrinsic Value, Exercised	521
Intrinsic Value, Exercisable	$ 11,475
Weighted Average Remaining Contractual Term (in Years)	5 years 4 months 24 days	6 years 7 months 6 days
Weighted Average Remaining Contractual Term (in Years), Exercisable	5 years 4 months 24 days
FEB Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Shares, Beginning balance	624,383
Number of Shares, Exercised	(113,214)	(56,404)
Number of Shares, Ending balance	511,169	624,383
Number of Shares, Exercisable	511,169
Weighted Average Exercise Price, Beginning balance	$ 11.31
Weighted Average Exercise Price, Exercised	11.17
Weighted Average Exercise Price, Ending balance	11.35	$ 11.31
Weighted Average Exercise Price, Exercisable	$ 11.35
Intrinsic Value, Outstanding	$ 4,204	$ 3,339
Intrinsic Value, Exercised	909
Intrinsic Value, Exercisable	$ 4,204
Weighted Average Remaining Contractual Term (in Years)	4 years 4 months 24 days	5 years 2 months 12 days
Weighted Average Remaining Contractual Term (in Years), Exercisable	4 years 4 months 24 days

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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

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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 price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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