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.

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)

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

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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

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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.

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- 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

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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

Net number of non-option equity instruments granted to participants.

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- Definition

Number of Employees Granted an Award

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- Definition

Percentage of Maximum Number of Shares Issued Under Plan to Aggregate Shares

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Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vesting Percentage

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Incentive Share Plan (Narrative) (Details) $ in Thousands			3 Months Ended		9 Months Ended
Incentive Share Plan (Narrative) (Details) $ in Thousands	Jun. 30, 2015 shares	Apr. 02, 2014 employee shares	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Dec. 22, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation			$ 1,859	$ 1,485	$ 5,202	$ 3,092
Minimum \| Time-Based Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		1 year
Maximum \| Time-Based Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		2 years
Restricted Common Shares and Restricted Share Units [Member] \| Time and Performance-Based Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of employees granted an award \| employee		51
Aggregate shares granted (in shares) \| shares		633,704
Restricted Common Shares and Restricted Share Units [Member] \| Time-Based Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate shares granted (in shares) \| shares	143,000
Restricted Common Shares and Restricted Share Units [Member] \| Performance Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate shares granted (in shares) \| shares		2,049,116
Non-Cash Share Based Compensation in 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost			7,100		7,100
Non-Cash Share Based Compensation Subsequent to 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost			$ 13,200		$ 13,200
Unrecognized compensation cost, period for recognition					28 months
2008 Long-Term Equity Incentive Ownership Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of maximum number of shares issued under plan to aggregate shares							12.50%
2008 Long-Term Equity Incentive Ownership Plan [Member] \| Restricted Common Shares and Restricted Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			82.00%		82.00%
2008 Long-Term Equity Incentive Ownership Plan [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost			$ 10,800		$ 10,800
Award vesting period					42 months
2008 Long-Term Equity Incentive Ownership Plan [Member] \| Non-Vested Time Based Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost			$ 4,200		$ 4,200
Unrecognized compensation cost, period for recognition					18 months