Long-term Compensation Plans - Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options (in shares)	0	256,202	390,198
Weighted average strike price (in dollars per share)		$ 13.30	$ 8.05
Weighted average grant date fair value (in dollars per share)		$ 6.05	$ 4.35
Weighted average exercise price of outstanding options (in dollars per share)	$ 13.30
Outstanding stock options vested (in shares)	207,708
Vested options outstanding, aggregate intrinsic value	$ 0.5
Nonvested options (in shares)	253,994
Aggregate intrinsic value of nonvested options	$ 0.2
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Award expiration period	10 years
Exercise Price $13.50
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of outstanding options (in shares)	75,070

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. 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 fully vested and expected to vest options outstanding that can be converted into shares under option plan. 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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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of non-vested options outstanding.

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