Shareholders' Equity and Share-Based Compensation Stock Option Activity (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning, options	7,513,088	8,156,269	7,960,170
Granted, options	445,767	700,300	1,494,250
Exercised, options	(1,485,784)	(522,218)	(415,156)
Canceled, options	(586,132)	(821,263)	(882,995)
Outstanding, ending, options	5,886,939	7,513,088	8,156,269
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding, beginning, weighted average exercise price	$ 10.34	$ 10.25	$ 10.26
Granted, weighted average exercise price	$ 10.85	$ 9.96	$ 10.13
Exercised, weighted average exercise price	$ 8.56	$ 7.62	$ 7.91
Canceled, weighted average exercise price	$ 12.38	$ 10.92	$ 11.22
Outstanding, ending, weighted average exercise price	$ 10.64	$ 10.34	$ 10.25
Exercisable, options	3,512,257	4,286,232	4,068,071		3,366,610
Exercisable, options, weighted average exercise price	$ 10.53	$ 10.12	$ 9.98		$ 10.31
Exercisable, options, weighted average remaining contractual life	4 years 9 months 1 day	4 years 3 months 20 days	4 years 2 months 13 days	4 years 3 months 20 days

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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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

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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.

+ References

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

-Publisher FASB

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-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iv)(3)-(4)

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

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-Publisher FASB

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-SubTopic 10

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

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No definition available.

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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 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.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

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