Share based compensation arrangement by share based payment awards exercise period.

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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 14
-Section F

+ Details

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Balance Type:	debit
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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

Unrecognized cost of unvested share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

+ Details

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Period Type:	duration

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Number of options outstanding, including both vested and non-vested options.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

+ Details

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Period Type:	duration

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Employee Benefits - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Compensation costs recognized in earnings	$ 14,882	$ 10,885	$ 2,923
Cash-Settled Stock Appreciation Rights
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Compensation costs recognized in earnings	8,900	$ 7,000
Total unrecognized compensation cost related to non-vested share awards	$ 13,600
Total unrecognized compensation cost related to non-vested awards, weighted average contractual life of awards (years)	1 year 6 months 11 days
Shares outstanding to employees	1,160,828	1,068,001
Time-Based Restricted Shares \| Long-term Incentive Plans
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Compensation costs recognized in earnings	$ 3,900	$ 5,200
Total unrecognized compensation cost related to non-vested share awards	$ 3,500
Total unrecognized compensation cost related to non-vested awards, weighted average contractual life of awards (years)	2 years 10 months 21 days
Minimum \| Cash-Settled Stock Appreciation Rights
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vested SARs exercisable period (years)	4 years
Minimum \| Time-Based Restricted Shares \| Atrium
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Awarded shares, vesting period (years)	2 years
Maximum \| Cash-Settled Stock Appreciation Rights
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vested SARs exercisable period (years)	10 years
Maximum \| Time-Based Restricted Shares \| Atrium
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Awarded shares, vesting period (years)	3 years
2006 Equity Incentive Plan
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Compensation costs recognized in earnings	$ 6,100	3,900	2,900
Total unrecognized compensation cost related to non-vested share awards	$ 5,500
Total unrecognized compensation cost related to non-vested awards, weighted average contractual life of awards (years)	1 year 8 months 12 days
Enstar Group Limited Employee Share Purchase Plan
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Compensation costs recognized in earnings	$ 300	$ 100	$ 100
Shares issued to employees	11,998	6,031	4,959