The additional payment per each increment of principal amount of convertible notes being redeemed.

No definition available.

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- Definition

The percentage of the principal amount of the notes to be purchased, plus accrued and unpaid interest, upon the occurrence of certain fundamental changes, as set forth in the indenture governing the convertible notes.

+ References

No definition available.

+ Details

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- Definition

The increment of principal amount of convertible notes being redeemed.

+ References

No definition available.

+ Details

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- Definition

Amount of noncash expense included in interest expense to allocate debt discount and premium, and the costs to issue debt and obtain financing over the related debt instruments. Alternate captions include noncash interest expense.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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- Definition

Carrying amount of long-term convertible debt as of the balance sheet date, net of the amount due in the next twelve months or greater than the normal operating cycle, if longer. The debt is convertible into another form of financial instrument, typically the entity's common stock.

+ References

+ Details

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Period Type:	instant

- References

No definition available.

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Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

+ References

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- Definition

The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

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-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
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- Definition

The price per share of the conversion feature embedded in the debt instrument.

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- Definition

The amount by which the convertible debt's if-converted value exceeds its principle amount at the balance sheet date, regardless of whether the instrument is currently convertible. This element applies to public companies only.

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- Definition

The number of equity instruments that the holder of the debt instrument would receive if the debt was converted to equity.

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- Definition

Remaining amortization period for discount on the liability component of convertible debt which may be settled in cash upon conversion, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (a)
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Period Type:	duration

- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instruments must exceed threshold percentage for a specified number of trading days to trigger conversion feature, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.

+ References

No definition available.

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Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.

+ References

No definition available.

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- Definition

Face (par) amount of debt instrument at time of issuance.

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-Publisher FASB
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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

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Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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- Definition

Date the debt instrument was issued, in CCYY-MM-DD format.

+ References

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- Definition

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

+ References

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- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
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- Definition

Face (par) amount of the original debt instrument that was repurchased.

+ References

No definition available.

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- Definition

The amount of debt discount (net of debt premium) that was originally recognized at the issuance of the instrument that has yet to be amortized.

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- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

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-Paragraph 2
-Subparagraph (bbb)
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- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 2
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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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- Definition

The cash inflow from the issuance of a long-term debt instrument which can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

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The cash outflow from the repayment of a long-term debt instrument which can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder.

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Long-Term Obligations and Commitments, Convertible Notes (Details)	1 Months Ended	12 Months Ended
	Nov. 30, 2014 USD ($)	Dec. 31, 2015 USD ($) shares d $ / shares	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Convertible Notes [Abstract]
Proceeds from issuance of 1 percent convertible senior notes, net of issuance costs		$ 0	$ 487,035,000	$ 0
Loss on early retirement of debt		0	(8,292,000)	0
Amortization of debt discount and debt issuance costs		23,200,000	9,600,000	$ 6,800,000
1 Percent Convertible Senior Notes [Member]
Convertible Notes [Abstract]
Long-term debt		347,214,000	327,486,000
2 3/4 Percent Convertible Senior Notes [Member]
Convertible Notes [Abstract]
Principal amount repurchased			140,000,000
Long-term debt		50,361,000	48,014,000
Convertible Senior Notes [Member] \| 1 Percent Convertible Senior Notes [Member]
Convertible Notes [Abstract]
Face amount of offering	$ 500,000,000
Proceeds from issuance of 1 percent convertible senior notes, net of issuance costs	487,000,000
Principal amount of convertible notes outstanding		$ 500,000,000	$ 500,000,000
Issue date		Nov. 30, 2014
Maturity date		Nov. 30, 2021
Interest rate		1.00%	1.00%
Conversion price per share (in dollars per share) \| $ / shares		$ 66.81
Total shares of common stock subject to conversion (in shares) \| shares		7,500,000
Percentage of principal amount used a purchase price upon occurrence of fundamental change		100.00%
Nonconvertible debt borrowing rate		7.40%
Effective interest rate		7.80%
Amortization period of debt discount		7 years
Fair value of outstanding notes		$ 555,000,000	$ 568,000,000
Unamortized portion of liability component		152,786,000	172,514,000
Long-term debt		347,214,000	327,486,000
Carrying value of equity component		174,770,000	174,770,000
Convertible Senior Notes [Member] \| 2 3/4 Percent Convertible Senior Notes [Member]
Convertible Notes [Abstract]
Principal amount repurchased	140,000,000
Repurchase of convertible senior notes	441,900,000
Principal amount of convertible notes outstanding	61,200,000	$ 61,247,000	$ 61,247,000
Loss on early retirement of debt	$ 8,300,000
Issue date		Aug. 31, 2012
Maturity date		Oct. 31, 2019
Interest rate		2.75%	2.75%	2.75%
Conversion price per share (in dollars per share) \| $ / shares		$ 16.63
Total shares of common stock subject to conversion (in shares) \| shares		3,700,000
Percentage of principal amount used a purchase price upon occurrence of fundamental change		100.00%
If-converted value of notes in excess of principal		$ 166,900,000
Nonconvertible debt borrowing rate		8.00%
Effective interest rate		8.80%
Amortization period of debt discount		7 years
Fair value of outstanding notes		$ 215,320,000	$ 223,900,000
Unamortized portion of liability component		10,886,000	13,233,000
Long-term debt		50,361,000	48,014,000
Carrying value of equity component		$ 18,714,000	$ 18,714,000
Convertible Senior Notes [Member] \| 2 3/4 Percent Convertible Senior Notes [Member] \| On or after October 5, 2016 [Member]
Convertible Notes [Abstract]
Threshold number of trading days to trigger redemption \| d		20
Threshold number of consecutive trading days to trigger redemption		30 days
Threshold percentage of conversion price to trigger redemption		130.00%
Percentage of principal amount used as redemption price		100.00%
Additional payment per $1,000 principal amount being redeemed		$ 90
Principal amount being redeemed		$ 1,000