Basic and Diluted Net IncomePer Share Anti-Dilutive Securities (Details)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options	2,841,000	3,465,000	2,555,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	2,841,000	3,465,000
Total equity award shares excluded	3,209,000	3,993,000	3,082,000
Semi-annual Performance Period, Maximum Multiplier of Original Grant	2.75
Entire Performance, Overall Achievement, Maximum Multiplier of Target Award	2.5
Convertible Debt Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total equity award shares excluded	2,110,000	2,110,000	3,517,000
Convertible Debt Securities [Member] \| 2013 Convertible Senior Notes [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total equity award shares excluded	0	0	2,450,000
Convertible Debt Securities [Member] \| 2015 Convertible Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total equity award shares excluded	2,110,000	2,110,000	1,067,000
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	128,000	335,000	527,000
Performance Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	240,000	193,000	0
Long-term Incentive Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	600,000.0	500,000.0

Entire Performance, Overall Achievement, Maximum Multiplier of Target Award

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Semi-annual Performance Period, Maximum Multiplier of Original Grant

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (c)

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Antidilution

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Diluted Earnings Per Share

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Contingent Stock Agreement

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(i)-(ii)

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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

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-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

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