Percentage of repurchase of class A common stock.

No definition available.

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- Definition

Stock Repurchased and Retired During Period, Per Share

+ References

No definition available.

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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

Face amount or stated value per share of common stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

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- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

+ References

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- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

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- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

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-Publisher FASB

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- Definition

Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.28)

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-Name Regulation S-X (SX)

-Number 210

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- Definition

The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

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-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.28)

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- Definition

Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.28)

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- Definition

The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

+ References

No definition available.

+ Details

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- Definition

The remaining number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

+ References

No definition available.

+ Details

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- Definition

Number of shares that have been repurchased and retired during the period.

+ References

+ Details

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- Definition

Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

+ References

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Share Capital - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended		39 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Sep. 15, 2015	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2013	Oct. 07, 2011
Class of Stock [Line Items]
Preferred stock, authorized (in shares)	50,000,000		50,000,000
Preferred stock, par value (dollars per share)	$ 0.001		$ 0.001
Preferred stock, issued (in shares)	0		0
Class A Stock [Member]
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	50,000,000		50,000,000		50,000,000
Common stock, par value (dollars per share)	$ 0.001		$ 0.001		$ 0.001
Common stock, shares issued (in shares)	13,333,368		13,333,368		13,530,688
Common stock, shares outstanding (in shares)	13,333,368	13,530,688	13,333,368	13,530,688	13,530,688	13,348,369	13,650,149	13,519,126	13,377,967
Repurchased and canceled pursuant to the stock buy-back (in shares)	328,844	0	328,844	0
Class A Stock [Member] \| New Program [Member]
Class of Stock [Line Items]
Common stock, shares issued (in shares)						13,348,369
Number of shares authorized to be repurchased (in shares)						665,000
Percentage of repurchase of class A common stock						5.00%
Remaining number of shares authorized to be repurchased (in shares)	665,000		665,000
Class A Stock [Member] \| Previous Program [Member]
Class of Stock [Line Items]
Number of shares authorized to be repurchased (in shares)										675,000
Repurchased and canceled pursuant to the stock buy-back (in shares)			328,844		322,177
Stock repurchased and retired during period, value			$ 6.6
Stock repurchased and retired during period (dollars per share)			$ 20.12
Remaining number of shares authorized to be repurchased (in shares)	23,979		23,979
Class B Stock [Member]
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	99,680		99,680		99,680
Common stock, par value (dollars per share)	$ 0.001		$ 0.001		$ 0.001
Common stock, shares issued (in shares)	99,680		99,680		99,680
Common stock, shares outstanding (in shares)	99,680		99,680		99,680