Represents the number of equity stock based compensation.

No definition available.

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- Definition

The percentage of target shares, an employee can earn, under the plan.

+ References

No definition available.

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

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- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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- Definition

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.

+ References

No definition available.

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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

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Period Type:	instant

- Definition

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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- Definition

Intrinsic value of vested award under share-based payment arrangement. Excludes share and unit options.

+ References

No definition available.

+ Details

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- Definition

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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- Details

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Stock-Based Compensation - Additional information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) plan shares	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity stock based compensation plans (plan) \| plan	2
Stock based compensation expense (reversal)	$ 4.4	$ 3.2	$ 4.4
Unrecognized stock-based compensation expense	$ 5.4
Long-Term Incentive Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares permitted for granting (in shares) \| shares	900,000
Performance awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of common stock at the time of vesting	$ 0.2	1.0	1.3
Unrecognized stock-based compensation expense	$ 2.6
Remaining weighted average vesting period	1 year 6 months
Performance awards [Member] \| Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period	2 years 9 months 18 days
Stock based compensation expense (reversal)		(0.7)
Performance awards [Member] \| Long-Term Incentive Plan [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of potential target shares awarded	0.00%
Performance awards [Member] \| Long-Term Incentive Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of potential target shares awarded	200.00%
Time vested stock awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of common stock at the time of vesting	$ 3.4	$ 3.0	$ 3.8
Unrecognized stock-based compensation expense	$ 2.8
Remaining weighted average vesting period	1 year 7 months 6 days
Time vested stock awards [Member] \| Long-Term Incentive Plan [Member] \| Share-based Payment Arrangement, Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period	3 years
Award vesting period	3 years
Time vested stock awards [Member] \| Long-Term Incentive Plan [Member] \| Share-based Payment Arrangement, Nonemployee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period	1 year	1 year	3 years
Award vesting period	1 year
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of options exercised	$ 0.2	$ 1.3	$ 1.7
Stock Options [Member] \| Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award expiration period	10 years