Stock Compensation - Summary of Stock Option Activity for the Period (Details) - $ / shares	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options Granted (in shares)	255,072	397,759	271,350
Issuances under option plans, shares	191,169	375,292	334,836
Outstanding at December 31, 2017	988,167	1,183,830
Options Exercised, Shares (in shares)	(191,169)	(375,292)	(334,836)
Cancelled or forfeited (in shares)	(86,411)
Outstanding at December 31, 2018	965,659	988,167	1,183,830
Exercisable at December 31, 2018	521,202	539,993	934,898
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Options Granted, Average Exercise Price (in dollars per share)	$ 21.30	$ 14.30	$ 11.62
Options Exercised, Average Exercise Price (in dollars per share)	14.30
Outstanding, Average Price (in dollars per share)	15.13
Cancelled or forfeited, average exercise price (in dollars per share)	17.65
Outstanding, Average Price (in dollars per share)	16.69	15.13
Exercisable, Average Exercise Price (in dollars per share)	$ 16.08	16.23	14.88
Outstanding, Weighted Average Life	7 years 2 months 23 days
Exercisable, Weighted Average Life	6 years 1 month 6 days
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Options Exercised, Average Exercise Price (in dollars per share)	$ 9.97	9.00	9.97
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Options Exercised, Average Exercise Price (in dollars per share)	$ 20.93	$ 14.77	$ 17.02

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

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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 of exercisable stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term of outstanding stock options, 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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