Benefit Plans (Details 1) (USD $) In Thousands, except Per Share data	9 Months Ended
Sep. 30, 2011
Restricted stock unit activity under the plans
Restricted stock units vested, Aggregate fair value	$ 7,800
Restricted Stock [Member]
Restricted stock unit activity under the plans
Balance at December 31, 2010, RSUs Outstanding	4,507
Balance at December 31, 2010, Weighted Average Fair value Per Share	$ 6.43
Balance at December 31, 2010, Aggregate fair value	0
Restricted stock units granted, RSUs Outstanding	1,856
Restricted stock units granted, Weighted Average Fair value Per Share	$ 9.03
Restricted stock units granted, Aggregate fair value	0
Restricted stock units vested, RSUs Outstanding	(1,212)
Restricted stock units vested, Weighted Average Fair value Per Share	$ 6.40
Restricted stock units vested, Aggregate fair value	9,846
Restricted stock units cancelled, RSUs Outstanding	(1,095)
Restricted stock units cancelled, Weighted Average Fair value Per Share	$ 7.00
Restricted stock units cancelled, Aggregate fair value	0
Balance at September 30, 2011, RSUs Outstanding	4,056
Balance at September 30, 2011, Weighted Average Fair value Per Share	$ 7.47
Balance at September 30, 2011, Aggregate fair value	$ 0

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Share based compensation arrangement by share based payment award equity instruments other than options granted in period fair value.

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Share based compensation arrangement by share based payment award equity instruments other than options nonvested fair value.

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Share based compensation arrangement by share based payment awards equity instruments other than options forfeited in period.

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Share based compensation arrangement by share based payment awards equity instruments other than options forfeited in period weighted average grant date fair value.

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- Definition

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

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- Definition

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).

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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

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Publisher FASB

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-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

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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.

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

-Publisher FASB

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-Paragraph A240

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-Subparagraph b(2)(b)

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ 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(2)(a)

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-Subparagraph b(2)(b)

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-Name Accounting Standards Codification

-Topic 718

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-Subparagraph (c)(2)(i)-(ii)

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- Definition

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

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- Definition

The total fair value of equity-based awards for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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