Stock-Based Compensation (Details 2) (USD $)	3 Months Ended
Mar. 31, 2013
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	998,874
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 7 months 17 days
Options Outstanding, Weighted Average Exercise Price	$ 9.24
Options Exercisable, Number	957,356
Options Exercisable, Weighted Average Exercise Price	$ 9.35
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	109,845
Options Outstanding, Weighted Average Contractual Life (Years)	5 years 1 month 28 days
Options Outstanding, Weighted Average Exercise Price	$ 6.53
Options Exercisable, Number	81,678
Options Exercisable, Weighted Average Exercise Price	$ 6.64
Range Two [Member]
Information about stock options outstanding under all stock plans
Lower range of exercise prices	$ 6.87
Upper range of exercise prices	$ 7.93
Options Outstanding, Number	104,076
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 3 months 26 days
Options Outstanding, Weighted Average Exercise Price	$ 7.62
Options Exercisable, Number	90,724
Options Exercisable, Weighted Average Exercise Price	$ 7.68
Range Three [Member]
Information about stock options outstanding under all stock plans
Lower range of exercise prices	$ 8.07
Upper range of exercise prices	$ 8.63
Options Outstanding, Number	104,037
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 6 months 18 days
Options Outstanding, Weighted Average Exercise Price	$ 8.55
Options Exercisable, Number	104,037
Options Exercisable, Weighted Average Exercise Price	$ 8.55
Range Four [Member]
Information about stock options outstanding under all stock plans
Lower range of exercise prices	$ 8.76
Upper range of exercise prices	$ 8.76
Options Outstanding, Number	44,000
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 10 months 21 days
Options Outstanding, Weighted Average Exercise Price	$ 8.76
Options Exercisable, Number	44,000
Options Exercisable, Weighted Average Exercise Price	$ 8.76
Range Five [Member]
Information about stock options outstanding under all stock plans
Lower range of exercise prices	$ 9.09
Upper range of exercise prices	$ 9.09
Options Outstanding, Number	100,000
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 4 months 2 days
Options Outstanding, Weighted Average Exercise Price	$ 9.09
Options Exercisable, Number	100,000
Options Exercisable, Weighted Average Exercise Price	$ 9.09
Range Six [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)	2 years 10 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 Seven [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)	3 years 4 months 2 days
Options Outstanding, Weighted Average Exercise Price	$ 9.16
Options Exercisable, Number	132,000
Options Exercisable, Weighted Average Exercise Price	$ 9.16
Range Eight [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	121,780
Options Outstanding, Weighted Average Contractual Life (Years)	2 years 11 months 12 days
Options Outstanding, Weighted Average Exercise Price	$ 9.70
Options Exercisable, Number	121,780
Options Exercisable, Weighted Average Exercise Price	$ 9.70
Range Nine [Member]
Information about stock options outstanding under all stock plans
Lower range of exercise prices	$ 10.46
Upper range of exercise prices	$ 11.00
Options Outstanding, Number	100,960
Options Outstanding, Weighted Average Contractual Life (Years)	1 year 8 months 16 days
Options Outstanding, Weighted Average Exercise Price	$ 10.72
Options Exercisable, Number	100,960
Options Exercisable, Weighted Average Exercise Price	$ 10.72
Range Ten [Member]
Information about stock options outstanding under all stock plans
Lower range of exercise prices	$ 11.01
Upper range of exercise prices	$ 11.84
Options Outstanding, Number	167,550
Options Outstanding, Weighted Average Contractual Life (Years)	1 year 22 days
Options Outstanding, Weighted Average Exercise Price	$ 11.50
Options Exercisable, Number	167,550
Options Exercisable, Weighted Average Exercise Price	$ 11.50

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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.

+ References

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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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