Share-Based Compensation (Details 1) - $ / shares	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Restricted Stock Units (RSUs) [Member]
Summary of restricted stock award activity
Nonvested, Beginning of Period	19,158
Granted	14,534
Vested	(217)
Forfeited	(335)
Nonvested, End of Period	33,140	19,158
Weighted Average Grant-Date Fair Value, Beginning of Period	$ 292.50
Weighted Average Grant-Date Fair Value, Granted	292.20
Weighted Average Grant Date Fair Value, Vested	353.40
Weighted Average Grant Date Fair Value, Forfeited	321.00
Weighted Average Grant-Date Fair Value, End of Period	$ 291.60	$ 292.50
Restricted Stock [Member]
Summary of restricted stock award activity
Nonvested, Beginning of Period	166,203
Granted	88,738
Vested	(28,341)
Forfeited	(14,094)
Nonvested, End of Period	212,506	166,203
Weighted Average Grant-Date Fair Value, Beginning of Period	$ 519.00
Weighted Average Grant-Date Fair Value, Granted	287.85
Weighted Average Grant Date Fair Value, Vested	863.85
Weighted Average Grant Date Fair Value, Forfeited	376.95
Weighted Average Grant-Date Fair Value, End of Period	$ 384.45	$ 519.00
Performance unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	1 year 6 months	1 year 7 months 6 days
Summary of restricted stock award activity
Nonvested, Beginning of Period	30,888
Granted	42,961
Vested	(10,051)
Forfeited	(13,787)
Nonvested, End of Period	50,011	30,888

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ 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)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
-Subparagraph (c)(2)(iii)(3)
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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).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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The weighted average fair value at grant date for nonvested equity-based awards issued 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
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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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-Publisher FASB
-Name Accounting Standards Codification
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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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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.

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- Definition

Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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