Deferred compensation arrangement with individual compensation expense (income).

No definition available.

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- Definition

Share based compensation number of deferrals.

+ References

No definition available.

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- Definition

Represents the expense 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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
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- Definition

Aggregate number of common shares reserved for future issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Number of common stock held in a trust that has been set up specifically to accumulate stock for the sole purpose of distribution to participating employees but not yet earned.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 25
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=109244457&loc=d3e16701-113920

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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Period Type:	duration

- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

+ References

+ Details

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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

+ References

+ Details

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- Definition

Date the equity-based award expires, in CCYY-MM-DD format.

+ References

+ Details

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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.

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

Percentage of vesting of share-based compensation awards.

+ References

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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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- Definition

Number of share options (or share units) exercised during the current period.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Share-Based Compensation - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) shares	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) Deferral shares	Sep. 30, 2017 USD ($) shares	Dec. 31, 2017 shares	May 10, 2016 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred shares and held by the rabbi trust	269,630		269,630		289,026
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for awards	800,000		800,000
Long Term Incentive Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for awards	100,000		100,000
Long Term Incentive Stock Option [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option issued under plan vest and expire			5 years
Long Term Incentive Stock Option [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option issued under plan vest and expire			10 years
Time-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expenses \| $	$ 100,000	$ 100,000	$ 300,000	$ 300,000
Compensation cost expected to be recognized over period \| $	700,000		$ 700,000
Weighted-average period			1 year 10 months 24 days
Performance-Based RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period			1 year 10 months 24 days
Performance-based compensation expense (income) \| $	1,300,000	900,000	$ 2,700,000	$ 1,800,000
Remaining compensation expense \| $	$ 5,500,000		$ 5,500,000
1999 Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercised, Number of Shares			0	0
Granted, Number of Shares			0
1999 Stock Option Plan [Member] \| Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expenses \| $			$ 0	$ 0
Long Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for awards	900,000		900,000
2016 Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for awards						1,000,000
Incentive plan expiry date			May 10, 2026
2016 Incentive Plan [Member] \| Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for awards						100,000
2016 Incentive Plan [Member] \| Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares reserved for awards						900,000
Long Term Incentive Plan Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercised, Number of Shares			3,500	0
Weighted-average period			1 year 6 months
Granted, Number of Shares			0	5,000
Long Term Incentive Plan Stock Option [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expenses \| $	$ 100,000	$ 100,000	$ 100,000	$ 100,000
Expected compensation cost related to unvested awards not yet recognized \| $	$ 100,000		$ 100,000
Long Term Incentive Plan Stock Option [Member] \| After One Year [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option awards vesting percentage			50.00%
Long Term Incentive Plan Stock Option [Member] \| After Two Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option awards vesting percentage			75.00%
Long Term Incentive Plan Stock Option [Member] \| After Three Years [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option awards vesting percentage			100.00%
Deferred Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of deferrals \| Deferral			2