Amount of increase (decrease) in standardized measure of discounted future net cash flow as a result of passage of time.

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Amount of noncash expense included in interest expense to issue debt and obtain financing associated with the related debt instruments. Alternate captions include noncash interest expense.

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Including the current and noncurrent portions, the carrying value of convertible subordinated debt, as of the balance sheet date, initially scheduled to be repaid after one year or beyond the normal operating cycle if longer. This form of debt 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, and places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

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

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

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

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

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For an unclassified balance sheet, the carrying amount (net of accumulated amortization) as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of convertible debt securities using the if-converted method.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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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.

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Convertible Subordinated Notes (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Feb. 09, 2016	Dec. 31, 2015	Mar. 19, 2014
Debt Instrument [Line Items]
Effect of dilutive securities, Convertible junior subordinated debentures (in shares)	300	351	150	351
Carrying Values of Liability and Equity Components, Convertible Subordinated Notes
Debt issuance costs	$ (1,422)		$ (1,422)			$ (1,445)
Amortization of debt issuance costs			420	$ 460
Convertible Subordinated Notes [Member]
Debt Instrument [Line Items]
Stated interest rate percentage							2.75%
Carrying Values of Liability and Equity Components, Convertible Subordinated Notes
Convertible subordinated notes, principal amount	143,750		143,750			143,750	$ 143,750
Unamortized discount of liability component	(23,873)		(23,873)			(25,754)
Debt issuance costs	(2,522)		(2,522)			(2,769)
Carrying value of the liability component	117,355		117,355		$ 143,750	115,227
Equity component carrying value	17,973		17,973			$ 17,973
Convertible subordinated notes, fair value	160,200		160,200
Contractual coupon interest expense	1,000	$ 1,000	2,000	2,000
Amortization of debt issuance costs	100	100	200	200
Accretion of discount, convertible subordinated notes	$ 1,000	$ 900	$ 1,900	$ 1,700
Effective interest rate percentage	2.75%		2.75%			6.75%