Debt - 2016 Convertible Notes (Details Textual) - Senior Convertible Notes 2016 $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($) Tradingday $ / shares	Mar. 31, 2016 USD ($)
Debt Instrument [Line Items]
Senior convertible notes face amount \| $		$ 230,000
Interest rate on senior convertible notes	4.25%	4.25%
Maturity date of 2016 convertible Notes	Mar. 15, 2036
Initial conversion rate of common stock	17.5843
Convertible Notes, initial conversion of Par Value Convertible Notes to common stock \| $	$ 1
Initial conversion price \| $ / shares	$ 56.87
Minimum quarterly dividends to adjust conversion rate \| $ / shares	$ 0.185
Percentage of par value of convertible notes to be settled in cash	100.00%
Rate of conversion price	130.00%
Debt instrument, convertible, threshold consecutive trading days \| Tradingday	30
Debt instrument, convertible, threshold trading days \| Tradingday	20

Minimum quarterly dividends to adjust conversion rate.

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- Definition

The percentage amount of the par value of debt that will be settled in cash.

+ References

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The amount of the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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

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

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

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

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