Stock-Based Compensation (Details 4) (USD $)	12 Months Ended
Dec. 31, 2012
Weighted average exercise price and remaining term information about significant option groups outstanding
Number Outstanding	447,359
Weighted-Average Remaining Term	5 years 1 month 6 days
Weighted-Average Exercise Price	$ 19.59
Aggregate Intrinsic Value	$ 2,175
Vested Options [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Number Outstanding	382,856
Weighted-Average Exercise Price	$ 21.06
Less than $10.00 [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Exercise Price Upper Range	$ 10.00
Number Outstanding	13,828
Weighted-Average Remaining Term	2 years 9 months 18 days
Weighted-Average Exercise Price	$ 3.57
Aggregate Intrinsic Value	2,175
Less than $10.00 [Member] \| Vested Options [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Number Outstanding	11,443
Weighted-Average Exercise Price	$ 2.77
$10.00 - $19.99 [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Exercise Price Lower Range	$ 10.00
Exercise Price Upper Range	$ 19.99
Number Outstanding	256,482
Weighted-Average Remaining Term	6 years 3 months 18 days
Weighted-Average Exercise Price	$ 12.70
Aggregate Intrinsic Value
$10.00 - $19.99 [Member] \| Vested Options [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Number Outstanding	194,364
Weighted-Average Exercise Price	$ 13.25
$20.00 - $29.99 [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Exercise Price Lower Range	$ 20.00
Exercise Price Upper Range	$ 29.99
Number Outstanding	119,249
Weighted-Average Remaining Term	4 years
Weighted-Average Exercise Price	$ 23.18
Aggregate Intrinsic Value
$20.00 - $29.99 [Member] \| Vested Options [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Number Outstanding	119,249
Weighted-Average Exercise Price	$ 23.18
$30.00 - $39.99 [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Exercise Price Lower Range	$ 30.00
Exercise Price Upper Range	$ 39.99
Number Outstanding	21,800
Weighted-Average Remaining Term	3 years
Weighted-Average Exercise Price	$ 36.22
Aggregate Intrinsic Value
$30.00 - $39.99 [Member] \| Vested Options [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Number Outstanding	21,800
Weighted-Average Exercise Price	$ 36.22
$40.00 - $49.99 [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Exercise Price Lower Range	$ 40.00
Exercise Price Upper Range	$ 49.99
Number Outstanding	5,500
Weighted-Average Remaining Term	2 years 8 months 12 days
Weighted-Average Exercise Price	$ 46.51
Aggregate Intrinsic Value
$40.00 - $49.99 [Member] \| Vested Options [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Number Outstanding	5,500
Weighted-Average Exercise Price	$ 46.51
$50.00 - $59.99 [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Exercise Price Lower Range	$ 50.00
Exercise Price Upper Range	$ 59.99
Number Outstanding	30,500
Weighted-Average Remaining Term	2 years 8 months 12 days
Weighted-Average Exercise Price	$ 53.94
Aggregate Intrinsic Value
$50.00 - $59.99 [Member] \| Vested Options [Member]
Weighted average exercise price and remaining term information about significant option groups outstanding
Number Outstanding	30,500
Weighted-Average Exercise Price	$ 53.94

Share based compensation shares authorized under stock option plans exercise price range aggregate Intrinsic value.

No definition available.

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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

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (g)

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

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- Definition

The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ 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)(i)-(ii)

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

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(a, b)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

+ References

+ Details

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- Definition

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

+ References

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- Definition

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.

+ References

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