Debt Instrument, Convertible, Beneficial Conversion Feature Adjustment, (Decrease) Increase

No definition available.

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- Definition

Debt Instrument, Convertible, Threshold Business Days

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Convertible, Threshold Consecutive Business Days

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Debt Default, Violation Or Event Of Default, Declaration By Note Holders, Percentage

+ References

No definition available.

+ Details

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of a written promise to pay a note, initially due after one year or beyond the operating cycle if longer, which can be exchanged for a specified amount of one or more securities (typically 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
-Topic 946
-SubTopic 210
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- Definition

Amount of a favorable spread to a debt holder between the amount of debt being converted and the value of the securities received upon conversion. This is an embedded conversion feature of convertible debt issued that is in-the-money at the commitment date.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21538-112644

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- Definition

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

+ References

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-Publisher FASB
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- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

+ References

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- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature.

+ References

No definition available.

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

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.

+ Details

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
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+ Details

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- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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-Publisher FASB
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+ Details

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- Definition

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

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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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- Definition

Fair value amount of debt instrument that was repurchased.

+ References

No definition available.

+ Details

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- Definition

Amount, after accumulated amortization, of debt discount.

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- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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- Definition

Amount, after accumulated amortization, of debt issuance costs classified as noncurrent. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

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- Definition

The cap rate on a price risk derivative such as a cap or collar. A payment or receipt is triggered if the market rate exceeds the cap rate on the contract.

+ References

No definition available.

+ Details

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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.

+ References

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- Definition

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

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The cash outflow for cost incurred directly with the issuance of a derivative security.

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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.

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Credit Facilities (Convertible Senior Notes and Capped Call Transactions) (Details)			12 Months Ended
	Apr. 03, 2017 USD ($)	Dec. 10, 2013 USD ($) d $ / shares $ / security	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2017 USD ($)
Line of Credit Facility [Line Items]
Proceeds from issuance of debt			$ 120,000,000	$ 0	$ 125,000,000
Loss on extinguishment of debt			(6,512,000)	0
Debt			208,253,000	177,178,000
Payments of derivative issuance costs		$ 7,400,000
Convertible Senior Notes \| 2.25% Convertible Senior Notes
Line of Credit Facility [Line Items]
Convertible notes, face amount		$ 86,250,000
Convertible notes, stated percentage		2.25%
Proceeds from issuance of debt		$ 82,600,000
Debt instrument, redemption price, percentage		100.00%
Convertible debt, conversion ratio		0.0416051
Convertible debt, conversion price (in dollars per share) \| $ / shares		$ 24.04
Debt instrument, debt default, declaration by note holders, percentage		25.00%
Debt instrument, fair value		$ 66,900,000
Debt instrument, embedded conversion option		19,300,000
Unamortized debt discount		$ 3,700,000
Debt issuance costs			200,000
Debt			17,400,000
Derivative, cap price \| $ / security		29.02
Convertible Senior Notes \| 2.25% Convertible Senior Notes \| Minimum
Line of Credit Facility [Line Items]
Interest Expense, Debt			1,100,000
Convertible Senior Notes \| 2.25% Convertible Senior Notes \| Maximum
Line of Credit Facility [Line Items]
Interest Expense, Debt			$ 1,500,000
Convertible Senior Notes \| 2.25% Convertible Senior Notes \| Other Assets
Line of Credit Facility [Line Items]
Unamortized debt discount		$ 2,900,000
Convertible Senior Notes \| 2.25% Convertible Senior Notes \| Other Assets \| Accounting Standards Update 2015-03
Line of Credit Facility [Line Items]
Debt issuance costs				(1,900,000)
Convertible Senior Notes \| 2.25% Convertible Senior Notes \| Additional Paid-In Capital
Line of Credit Facility [Line Items]
Unamortized debt discount		$ 800,000
Convertible Senior Notes \| 2.25% Convertible Senior Notes \| Long-term Debt \| Accounting Standards Update 2015-03
Line of Credit Facility [Line Items]
Debt issuance costs				$ 1,900,000
Convertible Senior Notes \| 2.25% Convertible Senior Notes \| On or after December 15, 2016
Line of Credit Facility [Line Items]
Convertible debt redemption, trading days threshold \| d		20
Convertible debt redemption, consecutive trading days threshold \| d		30
Convertible debt redemption, percentage of stock price trigger, percentage		130.00%
Debt instrument, redemption price, percentage		100.00%
Convertible Senior Notes \| 2.25% Convertible Senior Notes \| Business Day Immediately Preceding September 15, 2018
Line of Credit Facility [Line Items]
Convertible debt redemption, trading days threshold \| d		20
Convertible debt redemption, consecutive trading days threshold \| d		30
Convertible debt redemption, percentage of stock price trigger, percentage		130.00%
Debt instrument, redemption price, percentage		98.00%
Convertible debt redemption, business days threshold \| d		5
Convertible debt redemption, consecutive business days threshold		5 years
Convertible Senior Notes \| Convertible Senior Notes due 2018
Line of Credit Facility [Line Items]
Debt Instrument, Repurchase Amount	$ 68,000,000
Debt Instrument, Convertible, Beneficial Conversion Feature Adjustment, (Decrease) Increase	(2,200,000)
Loss on extinguishment of debt	(3,200,000)
Secured Debt \| Facility Agreement, Due 2023
Line of Credit Facility [Line Items]
Convertible notes, face amount	120,000,000
Convertible notes, stated percentage						6.87%
Deferred financing costs	$ 5,100,000					$ 4,500,000