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

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

+ Details

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

+ References

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- Definition

Expected term of share-based compensation awards, 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 S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.D.2)

-URI http://asc.fasb.org/extlink&oid=6793087&loc=d3e301413-122809

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (f)(2)(i)

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

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section D

-Subsection 2

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- Definition

The estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

No definition available.

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- Definition

The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

No definition available.

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- Definition

The maximum risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

No definition available.

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- Definition

The minimum risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

No definition available.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

-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 (d)(1)

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

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Employee And Non-Employee Benefit And Compensation Plans (Details 1) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate assumption, minimum	0.511%
Risk-free interest rate assumption, maximum	0.629%
Dividend yield assumption	0.00%
Expected volatility rate, minimum	60.80%
Expected volatility rate, maximum	61.25%
Expected term of compensation awards	3 years 8 months 12 days
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average fair market value per option granted	1.30
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Average fair market value per option granted	2.17
Service period-based options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate assumption, minimum	0.40%	0.17%	1.00%
Risk-free interest rate assumption, maximum	0.60%	2.09%	1.60%
Dividend yield assumption	0.00%	0.00%	0.00%
Expected volatility rate, minimum	61.80%	60.38%	61.80%
Expected volatility rate, maximum	63.48%	61.25%	63.80%
Expected term of compensation awards	3 years 8 months 12 days
Service period-based options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of compensation awards		1 year	2 years 6 months
Average fair market value per option granted	1.40	0.75	2.14
Service period-based options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of compensation awards		7 years	3 years 8 months 12 days
Average fair market value per option granted	2.17	2.56	2.61
Price-based options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate assumption, minimum		1.34%
Risk-free interest rate assumption, maximum		2.29%
Dividend yield assumption		0.00%
Expected volatility rate, minimum		59.72%
Expected volatility rate, maximum		60.55%
Price-based options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of compensation awards		5 months 16 days
Average fair market value per option granted		0.42
Price-based options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of compensation awards		2 years
Average fair market value per option granted		2.35
Price-based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate assumption, minimum	0.37%
Risk-free interest rate assumption, maximum	1.17%
Dividend yield assumption	0.00%
Expected volatility rate, minimum	67.83%
Expected volatility rate, maximum	70.20%
Price-based RSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of compensation awards	5 months 1 day
Estimated value of RSUs	0.87
Price-based RSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term of compensation awards	1 year 11 months 9 days
Estimated value of RSUs	4.43