Employee Stock Benefit Plans (Stock Option Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding balance at beginning of period	1,311,634	1,625,706	1,714,934
Granted	203,825	163,042	168,939
Exercised	(397,369)	(223,382)	(69,327)
Canceled	(129,310)	(253,732)	(188,840)
Outstanding balance at end of period	988,780	1,311,634	1,625,706	1,714,934
Exercisable balance at end of period	646,504	964,043	1,202,949
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, weighted-average exercise price, balance at beginning of period (in USD per share)	$ 14.47	$ 14.63	$ 15.58
Granted, weighted-average exercise price (in USD per share)	$ 19.05	$ 13.96	$ 16.72
Exercised, weighted-average exercise price (in USD per share)	$ 13.56	$ 5.52	$ 6.95
Canceled, weighted-average exercise price (in USD per share)	$ 27.58	$ 22.75	$ 27.90
Outstanding, weighted-average exercise price, balance at end of period (in USD per share)	$ 14.07	$ 14.47	$ 14.63	$ 15.58
Exercisable balance at end of period, weighted-average exercise price (in USD per share)	$ 12.61	$ 15.06	$ 16.14
Outstanding, weighted-average remaining contractual life	5 years	4 years	4 years	6 years
Outstanding, aggregate intrinsic value	$ 6,856	$ 7,651	$ 3,957	$ 6,710
Exercised, aggregate intrinsic value	3,257	2,694	681
Exercisable, aggregate intrinsic value	$ 5,422

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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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.

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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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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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Net number of share options (or share units) granted during the period.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Number of share options (or share units) exercised during the current period.

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