v3.19.1

Stock-Based Compensation - Stock Options Outstanding (Details) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at beginning of year (in shares)	1,363,444	1,599,976
Add: Granted (in shares)	373,750	260,600
Less: Exercised (in shares)	(230,894)	(358,332)
Less: Retired on exercise (in shares)	(37,240)	0
Less: Expired/cancelled/forfeited (in shares)	(37,200)	(138,800)
Outstanding at end of year (in shares)	1,431,860	1,363,444
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding at beginning of year (in dollars per share)	$ 8.01	$ 6.36
Add: Granted (in dollars per share)	11.44	12.38
Less: Exercised (in dollars per share)	5.67	4.65
Less: Retired on exercise (in dollars per share)	5.07	0.00
Less: Expired/cancelled/forfeited (in dollars per share)	7.34	5.87
Outstanding at end of year (in dollars per share)	$ 9.38	$ 8.01
Exercisable at end of year (in shares)	643,610	644,472
Exercisable at end of year (in dollars per share)	$ 7.78	$ 6.47

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- Definition

Share-Based Compensation Arrangement By Share-Based Payment Award, Options, Retired

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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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For presentations that combine terminations, 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 or that expired.

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

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

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