Long-Term Debt - Convertible Senior Notes Due 2022 (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 issuance costs	$ 810,000	833,000
Convertible Senior Notes Maturing May 2022
Debt Instrument [Line Items]
Interest rate (as a percent)	4.25%
Frequency of periodic payment	semi-annually
Maturity date	May 01, 2022
Initial conversion ratio	0.0719748
Aggregate number of shares | shares	2,519,118
Initial conversion price per share (USD per share) | $ / shares	$ 13.89
Increase in the conversion rate	0.0305887
Redemption price as a percentage of principal amount	100.00%
Unamortized debt discount and debt issuance costs			$ 1,500,000
Unamortized debt issuance costs	$ 200,000
Effective interest rate (as a percent)	4.80%		7.30%
Interest expense	$ 400,000	2,300,000
Coupon interest expense	$ 400,000	1,400,000
Amortization of debt issuance costs		$ 900,000
Convertible Senior Notes Maturing May 2022 | 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 May 2022 | 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