Long-Term Debt - Convertible Senior Notes Due 2023 (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Unamortized debt discount		$ 45,692,000
Interest expense	$ 23,489,000	30,538,000	$ 31,186,000
Amortization of debt issuance costs	$ 3,179,000	3,177,000	3,600,000
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	$ 300,000
Effective interest rate (as a percent)	4.80%	7.80%
Interest expense	$ 1,400,000	$ 6,600,000	8,900,000
Coupon interest expense	1,200,000	3,700,000	5,200,000
Amortization of debt issuance costs	$ 200,000
Amortization of debt discount and issuance costs		$ 2,900,000	$ 3,700,000
Convertible Senior Notes Maturing September 2023 | Maximum
Debt Instrument [Line Items]
Percentage of closing price of common stock to conversion price	130.00%
Number of trading days	20
Number of consecutive trading days	30
Convertible Senior Notes Maturing September 2023 | Minimum
Debt Instrument [Line Items]
Percentage of closing price of common stock to conversion price	97.00%
Number of trading days	5
Number of consecutive trading days	10