Stock-Based Compensation - Narrative (Detail) $ in Millions	3 Months Ended
Mar. 31, 2016 USD ($) vesting_type yr shares	Mar. 31, 2015 USD ($) shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of award vesting types \| vesting_type	3
Cash liability for performance-based units \| $	$ 0.0
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense \| $	$ 0.2	$ 0.0
Stock-based compensation, maximum number of unvested shares	453,000
Market Based Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, maximum number of unvested shares	136,000
Vesting period	8 years
Service Based Award
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense \| $	$ 0.0	$ 0.1
Vesting period	4 years
Expiration period	8 years
Options issued	1,000	13,000
Options, forfeitures in period	8,000	6,000
Deferred Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of shares vested in lieu of directors fees at the grant date	100.00%
Portion of Director fees matched to deferred stock units	25.00%
Vesting period of deferred stock	1 year
Minimum age required for meeting directors fees deferred vest criteria \| yr	65
Deferred Stock Units \| Director
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares issued to non-employee individual	5,000	2,000
Deferred stock units, performance-based stock units and restricted stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense \| $	$ 0.6	$ 0.2

Cash Liability for Performance-Based Units

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Minimum age required for meeting directors fees deferred vest criteria.

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Percentage of shares vested in lieu of directors fees at the grant date.

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Portion of director fees matched to deferred stock units.

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- Definition

Share based compensation arrangement by share based payment award equity instruments maximum number of unvested shares.

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- Definition

Share based compensation arrangement by share based payment deferred award vesting period.

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Number of Award Vesting Types

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The amount of expense, net of income tax, recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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- Definition

Number of shares issued pursuant to the terms of a deferred compensation arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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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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- Definition

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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Number of share instruments newly issued under a share-based compensation plan.

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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.

+ References

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