The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option 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)(1)(iii)

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

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

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Number of options outstanding, including both vested and non-vested options.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

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

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(i)-(ii)

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

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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.

+ 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

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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-Publisher FASB

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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Employee Benefits and Retirement Plans - Summary of Stock Options Outstanding and Exercisable (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Outstanding Stock Options	2,500	10,900	10,900	10,900
Outstanding Stock Options, Weighted Average Exercise Price	$ 21.21	$ 20.19	$ 20.19	$ 20.19
Exercisable Stock Options	2,500	10,900	10,900
Exercisable Stock Options, Weighted Average Exercise Price	$ 21.21	$ 20.19	$ 20.19
Range 1 [Member]
Outstanding Stock Options, Exercise Price Range, minimum	$ 19
Outstanding Stock Options, Exercise Price Range, maximum	$ 20
Outstanding Stock Options	1,000
Outstanding Stock Options, Weighted- Average Remaining Contractual Life	1 year
Outstanding Stock Options, Weighted Average Exercise Price	$ 19.95
Exercisable Stock Options	1,000
Exercisable Stock Options, Weighted Average Exercise Price	$ 19.95
Range 2 [Member]
Outstanding Stock Options, Exercise Price Range, minimum	$ 21
Outstanding Stock Options, Exercise Price Range, maximum	$ 23
Outstanding Stock Options	1,500
Outstanding Stock Options, Weighted- Average Remaining Contractual Life	1 year 6 months
Outstanding Stock Options, Weighted Average Exercise Price	$ 22.05
Exercisable Stock Options	1,500
Exercisable Stock Options, Weighted Average Exercise Price	$ 22.05
Range 3 [Member]
Outstanding Stock Options, Exercise Price Range, minimum	$ 19
Outstanding Stock Options, Exercise Price Range, maximum	$ 23
Outstanding Stock Options	2,500
Outstanding Stock Options, Weighted Average Exercise Price	$ 21.21
Exercisable Stock Options	2,500
Exercisable Stock Options, Weighted Average Exercise Price	$ 21.21