Long-Term Debt - Convertible Senior Notes Due 2023 (Details)	3 Months Ended
Mar. 31, 2021 USD ($) $ / shares shares	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Debt Instrument [Line Items]
Interest expense	$ 6,112,000	$ 7,394,000
Amortization of debt discount and issuance costs	$ 810,000	833,000
Convertible Senior Notes Maturing September 2023
Debt Instrument [Line Items]
Interest rate (as a percent)	4.125%
Frequency of periodic payment	semi-annually
Maturity date	Sep. 15, 2023
Initial conversion ratio	0.1056133
Aggregate number of shares \| shares	3,168,399
Initial conversion price per share (USD per share) \| $ / shares	$ 9.47
Increase in the conversion rate	0.0475260
Redemption price as a percentage of principal amount	100.00%
Unamortized debt discount and debt issuance costs			$ 3,100,000
Unamortized debt issuance costs	$ 400,000
Effective interest rate (as a percent)	4.80%		7.80%
Interest expense	$ 400,000	2,300,000
Coupon interest expense	300,000	1,300,000
Amortization of debt discount and issuance costs	$ 100,000	$ 1,000,000.0
Convertible Senior Notes Maturing September 2023 \| Minimum
Debt Instrument [Line Items]
Percentage of closing price of common stock to conversion price	130.00%
Number of trading days	5
Number of consecutive trading days	10
Convertible Senior Notes Maturing September 2023 \| Maximum
Debt Instrument [Line Items]
Percentage of closing price of common stock to conversion price	97.00%
Number of trading days	20
Number of consecutive trading days	30

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

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The increase in ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount under certain corporate activity .

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The number of shares that the holder of the call would receive if converted to equity.

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Amount of amortization expense attributable to debt issuance costs.

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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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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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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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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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Percentage of principal amount of debt redeemed.

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Amount of unamortized debt discount (premium) and debt issuance costs.

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

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