Debt And Other Long-Term Liabilities (Narrative Senior Unsecured Notes) (Details) (USD $)	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Debt Instrument [Line Items]
Proceeds from issurance of senior unsecured notes	$ 343,769,000	$ 0
Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Date entered into indenture	Mar. 12, 2013
Senior unsecured note, face amount	350,000,000
Proceeds from issurance of senior unsecured notes	$ 343,800,000
Interest rate, per year	6.00%
Debt Instrument, Maturity Date	Mar. 15, 2019
Percentage of principal amount of notes required to be offered to purchase the Notes upon a change in control	101.00%
Percentage of principal amount of notes required to be offered to purchase the Notes if certain asset sales are made	100.00%
Minimum percentage of aggregate principal amount of Notes required to declare the principal amount plus accrued and unpaid interest on the Notes to be immediately due and payable in event of default	25.00%
Debt instrument, covenant description	The terms of the Notes restrict our ability and the ability of certain of its subsidiaries to, among other things: incur additional indebtedness; create liens; pay dividends or make distributions in respect of capital stock; purchase or redeem capital stock; make investments or certain other restricted payments; sell assets; enter into transactions with stockholders or affiliates; or effect a consolidation or merger. However, these and other limitations set forth in the Indenture will be subject to a number of important qualifications and exceptions.
Senior Unsecured Notes [Member] \| Period, March 15, 2016 To March 14, 2017 [Member]
Debt Instrument [Line Items]
Redemption rate applicable to periods	103.00%
Senior Unsecured Notes [Member] \| Period, March 15, 2017 To March 14, 2018 [Member]
Debt Instrument [Line Items]
Redemption rate applicable to periods	101.50%
Senior Unsecured Notes [Member] \| Period, March 15, 2018 To March 15, 2019 [Member]
Debt Instrument [Line Items]
Redemption rate applicable to periods	100.00%
Senior Unsecured Notes [Member] \| Period, March 12, 2013 To March 14, 2016 [Member]
Debt Instrument [Line Items]
Redemption rate applicable to periods	100.00%
Redemption rate with proceeds of certain equity offerings	106.00%
Maximum aggregate principal amount of notes redeemable	35.00%
Minimum aggregate principal amount of Notes outstanding after redemption	65.00%
Convertible Debt [Member]
Debt Instrument [Line Items]
Interest rate, per year	4.00%
Debt Instrument, Maturity Date	Sep. 01, 2014

Date entered into indenture pursuant to which Senior Notes were issued.

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- Definition

Maximum aggregate principal amount of the Notes redeemable using proceeds of certain equity offerings.

+ References

No definition available.

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- Definition

Minimum aggregate principal amount of the Notes remaining outstanding after redemption using proceeds of certain equity offerings.

+ References

No definition available.

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- Definition

Minimum percentage of aggregate principal amount of Notes required to declare the principal amount plus accrued and unpaid interest on the Notes to be immediately due and payable in event of default.

+ References

No definition available.

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- Definition

Percentage of principal amount of notes required to be offered to purchase the Notes if we make certain asset sales and do not reinvest the proceeds or use such proceeds to repay certain debt.

+ References

No definition available.

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- Definition

Percentage of principal amount of notes required to be offered to purchase the Notes upon a change in control (as defined in the Indenture).

+ References

No definition available.

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- Definition

Percentage of principal required to redeem Note.

+ References

No definition available.

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- Definition

Percentage of principal required to redeem Note with the proceeds of certain equity offerings.

+ References

No definition available.

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- Definition

Description of minimum financial levels (for example, tangible net worth and working capital) and achievement of certain financial ratios (for example, working capital ratio and debt service coverage ratio), and adherence to certain clauses which generally require or restrict certain actions (for example, entering into a debt arrangement with equal or greater seniority, and selling or discontinuing a certain business segment or material subsidiary) to be in compliance with the covenant clauses of the debt agreement. May also include a discussion of the adverse consequences that would result if the entity violates or fails to satisfy the covenants.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 50

-Paragraph 3

-Subparagraph (g)

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- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

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-SubTopic 30

-Section 55

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-Number 21

-Paragraph 16, 20

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- Definition

Interest rate stated in the contractual debt agreement.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

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-Subparagraph (SX 210.5-02.22(a)(2))

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-Paragraph 2, 4

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- Definition

The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt.

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 19

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Glossary Financing Activities

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