Unrecognized cost of unvested share-based compensation awards.

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

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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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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

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ 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 (c)(2)(iii)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ 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)(3)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ 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 (d)(2)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The current assumption based on the most recent information available shares vesting percentage for performance nonvested equitybased awards.

+ References

No definition available.

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- Definition

The fair value at date of grant for nonvested performance equity based awards during the period.

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- Definition

Percent of shares earned to the target of equity instruments other than options, the maximum percentage of the range.

+ References

No definition available.

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Percent of shares earned to the target for equity instruments other than options, the minimum percentage of the range.

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No definition available.

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- Definition

Shares vesting for performance nonvested equity based awards based on the most recent information available.

+ References

No definition available.

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Share-Based Compensation Arrangements (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 23, 2013	Apr. 22, 2003	Apr. 28, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost	$ 2,500,000
Weighted average recognition period (in years)	1 year 10 months 13 days
Share Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share options exercised total intrinsic value	$ 1,000,000	$ 1,700,000	$ 812,000
Cliff vesting period	3 years	3 years
Time Based Nonvested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments other than options granted	11,630	24,400	29,725
Cliff vesting period	3 years		3 years
Performance Based Nonvested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity instruments other than options minimum shares earned to target percentage	0.00%
Equity instruments other than options maximum shares earned to target percentage	200.00%
Equity instruments other than options granted	21,140
Equity instruments other than options granted, grant date fair value	$ 34.66	$ 26.05	$ 23.65
Cliff vesting period	3 years	3 years	3 years
Equity instruments other than options, shares vesting percentages	140.00%	144.00%	140.00%
Equity instruments other than options, shares vesting	21,140	43,416	35,140
Minimum [Member] \| Share Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cliff vesting period			3 years
Minimum [Member] \| Time Based Nonvested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cliff vesting period		3 years
Maximum [Member] \| Share Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cliff vesting period			5 years
Maximum [Member] \| Time Based Nonvested Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cliff vesting period		5 years
2013 Stock Option and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized				1,748,250
Two Thousand Three Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized					600,000
Two Thousand Three Stock Incentive Plan [Member] \| Stock Options and Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized					200,000
Amended and Restated Two Thousand Three Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized						1,200,000
Amended and Restated Two Thousand Three Stock Incentive Plan [Member] \| Stock Options and Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized						400,000