Equity-Based Compensation (Details) (USD $)	1 Months Ended	9 Months Ended
Jan. 31, 2011	Sep. 30, 2011 year
2007 Equity Incentive Plan
Equity compensation plans
Number of options and restricted stock units granted (in shares)		3,762,425
Number of stock options expired or terminated (in shares)		1,238,485
Number of restricted stock units expired or terminated (in shares)		191,173
Stock options exercised (in shares)		35,338
Shares of common stock issued pursuant to vested restricted stock units (in shares)		99,326
Number of stock options outstanding (in shares)		1,568,821
Number of restricted stock units outstanding (in shares)		629,282
Remaining number of shares available for future grants (in shares)		1,278,105
Term of stock option grants (in years)		ten years
2007 Equity Incentive Plan \| Senior management
Equity compensation plans
Number of restricted stock units outstanding (in shares)		320,000
Number of restricted stock units outstanding subject to performance condition (in shares)		147,000
Number of restricted stock units granted (in shares)	380,000
Vesting rights for restricted stock units	These restricted stock units vest in a single installment on the earlier of (1) the fourth anniversary of the date of grant and (2) immediately prior to a change of control of the Company.
Minimum closing share price for awards to vest at a specified performance condition (in dollars per share)	$ 30.00
Fair value of restricted stock units (in dollars)		$ 1,500,000
Number of years in which compensation cost will be recognized (in years)		4
2000 Stock Plan
Equity compensation plans
Number of stock options outstanding (in shares)		444,181

The total number of restricted stock units outstanding that are subject to a performance condition tied to the price of the Company's common stock.

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Represents the minimum closing share price for awards to vest at a specified performance condition.

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Number of stock options and restricted stock units granted during the period.

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Number of shares issued during the period pursuant to Restricted Stock Units that became fully vested in the period.

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The weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, using a decimal to express in number of years.

+ References

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The date when the equity-based award expires as specified in the award agreement, which may be presented in a variety of ways (for example, year, month and year, day, month and year, quarter of a year).

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Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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The number of grants made 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).

+ References

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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).

+ References

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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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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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

+ References

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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.

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Number of share options (or share units) exercised during the current period.

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