Stock Incentive Plans (Details 3) (Stock options, USD $)	12 Months Ended
Dec. 31, 2012
Options Outstanding
Number (in shares)	857,468
Weighted-Average Exercise Price (in dollars per share)	$ 17.01
Weighted-Average Remaining Contractual Life	2 years 6 months 18 days
Intrinsic Value (in dollars)	$ 8
Options Exercisable
Number (in shares)	857,468
Intrinsic Value (in dollars)	$ 8
$ 4.49-7.53
Range of Exercise Prices
Low end of the range (in dollars per share)	$ 4.49
High end of the range (in dollars per share)	$ 7.53
Options Outstanding
Number (in shares)	105,000
Weighted-Average Exercise Price (in dollars per share)	$ 6.01
Weighted-Average Remaining Contractual Life	7 years
Options Exercisable
Number (in shares)	105,000
$ 16.00-16.03
Range of Exercise Prices
Low end of the range (in dollars per share)	$ 16.00
High end of the range (in dollars per share)	$ 16.03
Options Outstanding
Number (in shares)	156,439
Weighted-Average Exercise Price (in dollars per share)	$ 16.00
Weighted-Average Remaining Contractual Life	2 months 16 days
Options Exercisable
Number (in shares)	156,439
$ 17.12-19.74
Range of Exercise Prices
Low end of the range (in dollars per share)	$ 17.12
High end of the range (in dollars per share)	$ 19.74
Options Outstanding
Number (in shares)	596,029
Weighted-Average Exercise Price (in dollars per share)	$ 19.21
Weighted-Average Remaining Contractual Life	2 years 4 months 17 days
Options Exercisable
Number (in shares)	596,029

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of options outstanding.

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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 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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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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