Bonds interest rate assumption.

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- Definition

Convertible preferred stock redemption value.

+ References

No definition available.

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- Definition

Fair value assumption, expected dividend rate.

+ References

No definition available.

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- Definition

Fair value assumption expected term.

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No definition available.

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- Definition

Fair value assumption expected volatility rate.

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No definition available.

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- Definition

Fair value assumption risk free interest rate.

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No definition available.

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- Definition

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

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-Name Accounting Standards Codification
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- Definition

Period remaining until the derivative contract matures, 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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- 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

Fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as a liability.

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- Definition

Net Increase or Decrease in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
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- Definition

Maximum period of time the entity is hedging its exposure to variability in future cash flows for forecasted transactions, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Excludes forecasted transactions related to payment of variable interest on existing financial instruments.

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Amount to be paid per share that is classified as temporary equity by entity upon redemption. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

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Derivative Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Dec. 31, 2017	May 22, 2017
Derivatives, Fair Value [Line Items]
Maximum length of time, foreign currency cash flow hedge		48 months
Convertible Preferred Stock, Redemption Value	$ 300,000,000	$ 300,000,000
Fair value of embedded derivative liability	8,375,000	8,375,000	$ 4,685,000	$ 10,900,000
Change in fair value of redeemable preferred stock embedded derivative liability	$ (4,588,000)	$ (3,690,000)
Minimum [Member]
Derivatives, Fair Value [Line Items]
Derivative, Remaining Maturity		1 month
Maximum [Member]
Derivatives, Fair Value [Line Items]
Derivative, Remaining Maturity		48 months
Embedded derivative liability [Member]
Derivatives, Fair Value [Line Items]
Redemption per share	$ 56.324	$ 56.324
Debt instrument face value	$ 150,000,000	$ 150,000,000
Convertible Preferred Stock, Redemption Value	$ 300,000,000	$ 300,000,000
Risky bond rate	19.30%	19.30%
Embedded derivative liability [Member] \| Price Volatility [Member]
Derivatives, Fair Value [Line Items]
Volatility rate	33.00%
Embedded derivative liability [Member] \| Expected Dividend Rate [Member]
Derivatives, Fair Value [Line Items]
Dividend yield rate	2.00%
Embedded derivative liability [Member] \| Minimum [Member] \| Expected Term [Member]
Derivatives, Fair Value [Line Items]
Valuation scenario term	3 years 6 months
Embedded derivative liability [Member] \| Minimum [Member] \| Risk Free Interest Rate [Member]
Derivatives, Fair Value [Line Items]
Risk-free interest rate	2.70%
Embedded derivative liability [Member] \| Maximum [Member] \| Expected Term [Member]
Derivatives, Fair Value [Line Items]
Valuation scenario term	5 years 10 months 20 days
Embedded derivative liability [Member] \| Maximum [Member] \| Risk Free Interest Rate [Member]
Derivatives, Fair Value [Line Items]
Risk-free interest rate	2.80%