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Convertible Securities - Additional Information (Details) - Junior Convertible Securities	Aug. 10, 2018 USD ($) trading_day $ / shares	Aug. 09, 2018	Dec. 31, 2018 USD ($)
Debt Instrument
Stated interest rate			5.15%
Principal amount at maturity | $	$ 50.00
Conversion ratio (in shares)	0.2525	0.2500
Conversion price (in usd per share) | $ / shares	$ 198.02
Redemption closing price trigger (in usd per share) | $ / shares	$ 257.43
Number of trading days closing price has exceeded threshold | trading_day	20
Number of consecutive trading days | trading_day	30
Deferred tax liability | $			$ 7,800,000

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- Definition

Debt Instrument, Individual Security, Face Amount

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Represents the deferred taxes generated from the excess of the interest expense calculated under federal income tax regulations over interest expense as calculated for book purposes.

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

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-Section 50
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Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

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Price of the entity's common stock which would be required to be attained for the conversion feature embedded in the debt instrument to become effective.

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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.

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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.

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

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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.

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