Shareholders' Equity and Stock Options (Details 2) (USD $)				12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 $6.91-$9.04 [Member]	Dec. 31, 2012 $13.83-$16.81 [Member]	Dec. 31, 2012 $17.01-$20.23 [Member]	Dec. 31, 2012 $6.91-$20.23 [Member]
Summary of options outstanding segregated by ranges of exercise prices
Range of Option Prices per Share, Lower limit				$ 6.91	$ 13.83	$ 17.01	$ 6.91
Range of Option Prices per Share, Upper limit				$ 9.04	$ 16.81	$ 20.23	$ 20.23
Total Outstanding Options, Options	1,882,939	2,600,583		415,346	687,185	780,408	1,882,939
Total Outstanding Options, Weighted Average Option Price per Share	$ 14.73	$ 15.13		$ 7.95	$ 15.14	$ 17.97	$ 14.73
Total Outstanding Options, Weighted Average Remaining Term				3 years 1 month 6 days	3 years	4 years 6 months	3 years 7 months 6 days
Vested and Exercisable Options	1,161,703	1,873,149		338,572	538,409	284,722	1,161,703
Vested and Exercisable Options, Weighted Average Option Price per Share		$ 15.57	$ 17.03	$ 8.19	$ 15.44	$ 19.31	$ 14.28
Vested and Exercisable Options, Weighted Average Remaining Term				3 years	2 years 8 months 12 days	2 years 2 months 12 days	2 years 8 months 12 days

Share based compensation arrangement by share based payment award options vested and exercisable outstanding number.

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- Definition

Share based compensation arrangement by share based payment award options vested and exercisable weighted average exercise price.

+ References

No definition available.

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- Definition

Share based compensation arrangement by share based payment award options vested and exercisable weighted average remaining contractual term.

+ References

No definition available.

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- Definition

The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

Reference 2: 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

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-Name Accounting Standards Codification

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(a)

-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

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

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(i)

-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)

-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

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

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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 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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