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- Definition

Percentage of closing market price paid for purchase of common stock shares through employee stock purchase plan.

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- Definition

The floor of a customized range of grant date fair values for purposes of disclosing shares potentially issuable under restricted stock awards on all restricted stock plans and other required information pertaining to awards in the customized range.

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The ceiling of a customized range of grant date fair values for purposes of disclosing shares potentially issuable under restricted stock awards on all restricted stock plans and other required information pertaining to awards in the customized range.

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Number of committed-to-be-released shares held by the Employee Stock Purchase Plan. Committed-to-be-released shares are shares that will be released in the future.

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Number of reserved shares held by the Employee Stock Purchase Plan.

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The maximum percentage rate stock-based compensation expense is calculated using net of forfeitures estimated from shares granted.

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The estimated measure of the percentage of shares, units or grants expected to be forfeited.

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Number of shares granted during the period related to Restricted Stock Awards, net of any shares forfeited.

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Grant date fair value of stock related to Restricted Stock Awards granted during the period.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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

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-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Stock Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Omnibus Stock Incentive Plan [Member]	Mar. 31, 2011 Omnibus Stock Incentive Plan [Member]	Sep. 30, 2011 Omnibus Stock Incentive Plan [Member]	Sep. 30, 2010 Omnibus Stock Incentive Plan [Member]	Sep. 30, 2011 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense related to stock-based compensation	$ 5,221	$ 5,823	$ 14,316	$ 15,799
Percentage of estimated forfeitures, minimum (in hundredths)							0.00%	0.00%
Percentage of estimated forfeitures, maximum (in hundredths)							10.00%	5.00%
Shares Granted (in shares)					1,957,000	70,000
Value Per Share, minimum (in dollars per share)					$ 13.75	$ 21.41
Value Per Share, maximum (in dollars per share)					$ 24.60	$ 23.45
Total Value					$ 31,173	$ 1,637
Percentage payroll deduction that each employee may deduct (in hundredths)									15.00%
Percentage of closing market price paid for purchase of whole shares (in hundredths)									90.00%
Initial number of shares reserved (in shares)									1,000,000
Annual increase in number of shares available for issuance (in shares)									200,000