Stock Based Compensation (Awards of Restricted Stock) (Details) (USD $)	3 Months Ended
Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Granted	21,780
Grant Date Fair Value	$ 40.03
2/11/2015 \| 2005 Employee Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Granted	31,500
Grant Date Fair Value	$ 39.42
Vesting Period	Ratably over 5 years from grant date
2/12/2015 \| 2005 Employee Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Granted	25,910
Grant Date Fair Value	$ 40.03
Vesting Period	Ratably over 5 years from grant date
3/19/2015 \| 2005 Employee Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Granted	3,800
Grant Date Fair Value	$ 43.56
Vesting Period	Ratably over 5 years from grant date

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).

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

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

+ 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)(1)

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

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- Definition

Description of pertinent provisions of equity-based compensation awards that have actual or potential impact upon the company's financial statements.

+ 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)

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

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