Stockholders Equity (Details 2) (USD $)	12 Months Ended
Dec. 31, 2012
$ 8.00 to $24.99 [Member]
Stock options outstanding
Number of Outstanding Options	478,697
Weighted Average Remaining Contractual Life	5 years 8 months 12 days
Weighted Average Exercise	$ 19.42
Number of Exercisable Options	396,690
Exercisable Options, Weighted Average Exercise Price	$ 18.36
$25.00 to $44.99 [Member]
Stock options outstanding
Number of Outstanding Options	1,074,221
Weighted Average Remaining Contractual Life	6 years 3 months 18 days
Weighted Average Exercise	$ 38.76
Number of Exercisable Options	561,591
Exercisable Options, Weighted Average Exercise Price	$ 41.33
$45.00 to $65.00 [Member]
Stock options outstanding
Number of Outstanding Options	32,676
Weighted Average Remaining Contractual Life	9 months 18 days
Weighted Average Exercise	$ 49.04
Number of Exercisable Options	32,676
Exercisable Options, Weighted Average Exercise Price	$ 49.04
$ 8.00 to $65.00 [Member]
Stock options outstanding
Number of Outstanding Options	1,585,594
Weighted Average Remaining Contractual Life	6 years
Weighted Average Exercise	$ 33.13
Number of Exercisable Options	990,957
Exercisable Options, Weighted Average Exercise Price	$ 32.39

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Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

+ References

+ Details

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- Definition

The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(c)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 (c)(iii)

-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

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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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