Stock-Based Compensation (Details 2) (USD $)	6 Months Ended
Jun. 30, 2012
Information about stock options outstanding under all stock plans
Lower Range of Exercise Prices	$ 5.50
Upper Range of Exercise Prices	$ 11.84
Options Outstanding, Number	1,196,012
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 11 months 5 days
Options Outstanding, Weighted Average Exercise Price	$ 9.17
Options Exercisable, Number	1,176,419
Options Exercisable, Weighted Average Exercise Price	$ 9.22
Range One [Member]
Information about stock options outstanding under all stock plans
Lower Range of Exercise Prices	$ 5.50
Upper Range of Exercise Prices	$ 6.86
Options Outstanding, Number	122,687
Options Outstanding, Weighted Average Contractual Life (Years)	4 years 10 months 2 days
Options Outstanding, Weighted Average Exercise Price	$ 6.64
Options Exercisable, Number	111,598
Options Exercisable, Weighted Average Exercise Price	$ 6.68
Range Two [Member]
Information about stock options outstanding under all stock plans
Lower Range of Exercise Prices	$ 6.87
Upper Range of Exercise Prices	$ 7.84
Options Outstanding, Number	121,536
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 1 month 6 days
Options Outstanding, Weighted Average Exercise Price	$ 7.46
Options Exercisable, Number	113,061
Options Exercisable, Weighted Average Exercise Price	$ 7.49
Range Three [Member]
Information about stock options outstanding under all stock plans
Lower Range of Exercise Prices	$ 7.85
Upper Range of Exercise Prices	$ 8.62
Options Outstanding, Number	176,372
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 7 months 10 days
Options Outstanding, Weighted Average Exercise Price	$ 8.26
Options Exercisable, Number	176,372
Options Exercisable, Weighted Average Exercise Price	$ 7.26
Range Four [Member]
Information about stock options outstanding under all stock plans
Lower Range of Exercise Prices	$ 8.63
Upper Range of Exercise Prices	$ 9.09
Options Outstanding, Number	164,000
Options Outstanding, Weighted Average Contractual Life (Years)	3 years 3 months 4 days
Options Outstanding, Weighted Average Exercise Price	$ 8.95
Options Exercisable, Number	164,000
Options Exercisable, Weighted Average Exercise Price	$ 8.95
Range Five [Member]
Information about stock options outstanding under all stock plans
Lower Range of Exercise Prices	$ 9.11
Upper Range of Exercise Prices	$ 9.12
Options Outstanding, Number	14,627
Options Outstanding, Weighted Average Contractual Life (Years)	3 years 7 months 2 days
Options Outstanding, Weighted Average Exercise Price	$ 9.12
Options Exercisable, Number	14,627
Options Exercisable, Weighted Average Exercise Price	$ 9.12
Range Six [Member]
Information about stock options outstanding under all stock plans
Lower Range of Exercise Prices	$ 9.16
Upper Range of Exercise Prices	$ 9.16
Options Outstanding, Number	132,000
Options Outstanding, Weighted Average Contractual Life (Years)	4 years 1 month 2 days
Options Outstanding, Weighted Average Exercise Price	$ 9.16
Options Exercisable, Number	132,000
Options Exercisable, Weighted Average Exercise Price	$ 9.16
Range Seven [Member]
Information about stock options outstanding under all stock plans
Lower Range of Exercise Prices	$ 9.19
Upper Range of Exercise Prices	$ 10.25
Options Outstanding, Number	131,780
Options Outstanding, Weighted Average Contractual Life (Years)	3 years 9 months 7 days
Options Outstanding, Weighted Average Exercise Price	$ 9.67
Options Exercisable, Number	131,780
Options Exercisable, Weighted Average Exercise Price	$ 9.67
Range Eight [Member]
Information about stock options outstanding under all stock plans
Lower Range of Exercise Prices	$ 10.46
Upper Range of Exercise Prices	$ 10.75
Options Outstanding, Number	121,460
Options Outstanding, Weighted Average Contractual Life (Years)	1 year 7 months 24 days
Options Outstanding, Weighted Average Exercise Price	$ 10.68
Options Exercisable, Number	121,431
Options Exercisable, Weighted Average Exercise Price	$ 10.68
Range Nine [Member]
Information about stock options outstanding under all stock plans
Lower Range of Exercise Prices	$ 10.80
Upper Range of Exercise Prices	$ 11.38
Options Outstanding, Number	147,050
Options Outstanding, Weighted Average Contractual Life (Years)	1 year 10 months 2 days
Options Outstanding, Weighted Average Exercise Price	$ 11.23
Options Exercisable, Number	147,050
Options Exercisable, Weighted Average Exercise Price	$ 11.23
Range Ten [Member]
Information about stock options outstanding under all stock plans
Lower Range of Exercise Prices	$ 11.55
Upper Range of Exercise Prices	$ 11.84
Options Outstanding, Number	64,500
Options Outstanding, Weighted Average Contractual Life (Years)	1 year 6 months 15 days
Options Outstanding, Weighted Average Exercise Price	$ 11.78
Options Exercisable, Number	64,500
Options Exercisable, Weighted Average Exercise Price	$ 11.78

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Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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- Definition

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 number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

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The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

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The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

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Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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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