Benefit Plans (Details 3) (USD $) In Thousands, except Per Share data, unless otherwise specified	9 Months Ended
Sep. 30, 2011 Year	Dec. 31, 2010
Stock options outstanding
Stock Options Outstanding, Number Outstanding at September 30, 2011	9,060	11,020
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	3.8
Stock Option Outstanding, Weighted Average Exercise Price Per Option	$ 7.08	$ 6.90
Options vested and exercisable at September 30, 2011, Stock Options Outstanding	6,592
Stock Options Exercisable, Weighted Average Exercise Price Per Option	$ 7.21
Exercise Price Range One [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 0.19
Range of Exercise Prices, Upper Limit	$ 4.80
Stock Options Outstanding, Number Outstanding at September 30, 2011	1,332
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	6.3
Stock Option Outstanding, Weighted Average Exercise Price Per Option	$ 2.61
Options vested and exercisable at September 30, 2011, Stock Options Outstanding	765
Stock Options Exercisable, Weighted Average Exercise Price Per Option	$ 2.60
Exercise Price Range Two [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 4.84
Range of Exercise Prices, Upper Limit	$ 5.87
Stock Options Outstanding, Number Outstanding at September 30, 2011	1,636
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	3.2
Stock Option Outstanding, Weighted Average Exercise Price Per Option	$ 5.70
Options vested and exercisable at September 30, 2011, Stock Options Outstanding	1,293
Stock Options Exercisable, Weighted Average Exercise Price Per Option	$ 5.70
Exercise Price Range Three [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 5.88
Range of Exercise Prices, Upper Limit	$ 8.12
Stock Options Outstanding, Number Outstanding at September 30, 2011	1,032
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	4.6
Stock Option Outstanding, Weighted Average Exercise Price Per Option	$ 6.65
Options vested and exercisable at September 30, 2011, Stock Options Outstanding	558
Stock Options Exercisable, Weighted Average Exercise Price Per Option	$ 6.72
Exercise Price Range Four [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 8.17
Range of Exercise Prices, Upper Limit	$ 8.17
Stock Options Outstanding, Number Outstanding at September 30, 2011	1,845
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	3.4
Stock Option Outstanding, Weighted Average Exercise Price Per Option	$ 8.17
Options vested and exercisable at September 30, 2011, Stock Options Outstanding	1,569
Stock Options Exercisable, Weighted Average Exercise Price Per Option	$ 8.17
Exercise Price Range Five [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 8.20
Range of Exercise Prices, Upper Limit	$ 8.65
Stock Options Outstanding, Number Outstanding at September 30, 2011	1,297
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	2.4
Stock Option Outstanding, Weighted Average Exercise Price Per Option	$ 8.25
Options vested and exercisable at September 30, 2011, Stock Options Outstanding	1,286
Stock Options Exercisable, Weighted Average Exercise Price Per Option	$ 8.25
Exercise Price Range Six [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 8.69
Range of Exercise Prices, Upper Limit	$ 9.69
Stock Options Outstanding, Number Outstanding at September 30, 2011	1,336
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	4.8
Stock Option Outstanding, Weighted Average Exercise Price Per Option	$ 9.39
Options vested and exercisable at September 30, 2011, Stock Options Outstanding	542
Stock Options Exercisable, Weighted Average Exercise Price Per Option	$ 9.04
Exercise Price Range Seven [Member]
Stock options outstanding
Range of Exercise Prices, Lower Limit	$ 9.74
Range of Exercise Prices, Upper Limit	$ 13.67
Stock Options Outstanding, Number Outstanding at September 30, 2011	582
Stock Option Outstanding, Weighted-Average Remaining Contractual Life	1.0
Stock Option Outstanding, Weighted Average Exercise Price Per Option	$ 10.35
Options vested and exercisable at September 30, 2011, Stock Options Outstanding	579
Stock Options Exercisable, Weighted Average Exercise Price Per Option	$ 10.55

Summarized information regarding stock options outstanding.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ References

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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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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The weighted average price as of the beginning of the year at which grantees can acquire the shares reserved for issuance under the stock option plan.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

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The weighted-average period between the balance sheet date and expiration date for fully vested and expected to vest options outstanding, which may be expressed in a decimal value for number of years.

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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.

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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.

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