Debt - Additional Information (Details)				1 Months Ended							3 Months Ended	12 Months Ended
	May 14, 2021 USD ($)	May 06, 2021 USD ($)	Jun. 14, 2017 USD ($)	May 31, 2021 USD ($)	Aug. 31, 2019 USD ($)	Jul. 31, 2019	May 31, 2019 USD ($)	Apr. 30, 2019	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2022 USD ($) $ / shares	Jun. 30, 2021 USD ($)	Jul. 01, 2021 USD ($)	Aug. 31, 2017 USD ($)	Apr. 30, 2014
Debt Instrument [Line Items]
Loss on extinguishment of debt												$ 0	$ 9,948,000
Debt discount costs												0
Principal amount of the Notes												183,865,000
Unamortized debt costs												3,395,000
Increase to accumulated deficit											$ (488,024,000)	(492,522,000)	(488,024,000)
Decrease to additional paid in capital											554,680,000	543,211,000	554,680,000
Revolving Credit Facility
Debt Instrument [Line Items]
Loss on extinguishment of debt	$ 1,400,000
Initial borrowing capacity			$ 52,000,000.0
Minimum drawn balance (as a percent)			30.00%
Principal amount of the Notes												5,000,000
Term loan
Debt Instrument [Line Items]
Principal amount of the Notes											80,000,000	76,000,000.0	80,000,000
New Revolving Credit Facility
Debt Instrument [Line Items]
Initial borrowings	25,000,000
Principal amount of the Notes											20,000,000.0	5,000,000.0	20,000,000.0
Unamortized debt costs											$ 1,300,000	$ 1,000,000.0	$ 1,300,000
90-day LIBOR | Revolving Credit Facility
Debt Instrument [Line Items]
Interest rate determination basis												90-day LIBOR
Variable rate (as a percent)			4.50%				3.50%	4.50%
3.75% Convertible Notes Due 2022
Debt Instrument [Line Items]
Aggregate principal amount of debt issued															$ 85,000,000.0
Interest rate (as a percent)				3.75%							3.75%	3.75%	3.75%		3.75%
Conversion rate, number of shares to be issued per $1000 of principal amount (in shares)												174.8252
Principal amount used for debt instrument conversion ratio												$ 1,000
Conversion price (in dollars per share) | $ / shares												$ 5.72
Repurchase price, as a percentage of the principal amount, in the event of a fundamental change, as defined in Indenture												100.00%
Convertible notes exchanged				$ 82,100,000
Convertible notes, aggregate principal amount outstanding											$ 2,900,000	$ 2,900,000	$ 2,900,000
Loss on extinguishment of debt												4,300,000
Extinguishment of equity component												14,500,000
Settlement consideration paid												96,000,000.0
Debt instrument, fair value of liability component												81,500,000
Debt discount costs												0
Principal amount of the Notes												2,865,000
Unamortized debt costs												$ 1,000
3.50% Convertible Notes Due 2018
Debt Instrument [Line Items]
Interest rate (as a percent)																3.50%
3.50% Series A Convertible Senior Notes Due 2018
Debt Instrument [Line Items]
Interest rate (as a percent)																3.50%
3.75% Convertible Notes Due 2026
Debt Instrument [Line Items]
Aggregate principal amount of debt issued				$ 100,000,000.0
Interest rate (as a percent)				3.75%							3.75%	3.75%	3.75%	3.75%
Conversion rate, number of shares to be issued per $1000 of principal amount (in shares)												170.5611
Principal amount used for debt instrument conversion ratio												$ 1,000
Conversion price (in dollars per share) | $ / shares												$ 5.86
Repurchase price, as a percentage of the principal amount, in the event of a fundamental change, as defined in Indenture												100.00%
Convertible notes exchanged				$ 97,100,000
Convertible notes, aggregate principal amount outstanding											$ 100,000,000.0	$ 100,000,000.0	$ 100,000,000.0
Convertible notes, aggregate principal amount issued for cash				$ 2,900,000
Debt discount costs												0
Principal amount of the Notes												100,000,000
Unamortized debt costs												$ 2,381,000
3.75% Convertible Notes Due 2026 | New Qualified Investors
Debt Instrument [Line Items]
Interest rate (as a percent)												3.75%		3.75%
Extinguishment of equity component												$ 25,900,000
Debt instrument, fair value of liability component												74,100,000
Convertible notes, aggregate principal amount issued for cash												2,900,000
Reduction in debt issuance cost allocated to additional paid in capital												$ 700,000
Increase to accumulated deficit														$ 800,000
Decrease to additional paid in capital														25,600,000
Increase to convertible debt, current														$ 24,800,000
3.75% Convertible Notes due 2022 and 3.75% Convertible Notes due 2026
Debt Instrument [Line Items]
Interest rate (as a percent)												3.75%
Discounts, issuance costs and third party costs												$ 25,600,000
Issuance costs attributable to liability component amortized												$ 800,000
Exchange | 3.75% Convertible Notes Due 2022
Debt Instrument [Line Items]
Aggregate principal amount of debt issued															$ 53,000,000.0
Exchange | 3.50% Convertible Notes due 2018 and 3.5% Series A Senior Notes due 2018
Debt Instrument [Line Items]
Aggregate principal amount of debt issued															47,000,000.0
Repurchase
Debt Instrument [Line Items]
Repurchase/Retirement of existing notes															28,000,000.0
Repurchase | 3.75% Convertible Notes Due 2022
Debt Instrument [Line Items]
Aggregate principal amount of debt issued															$ 32,000,000.0
Prior Revolving Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Reduced borrowing capacity										$ 32,000,000.0
Prior Term Loan
Debt Instrument [Line Items]
Loss on extinguishment of debt	$ 4,300,000
Prior Term Loan | Term Loan Facility
Debt Instrument [Line Items]
Initial term loan borrowing capacity										40,000,000.0
Additional term loan borrowing capacity										$ 20,000,000.0
Loan prepayment fees for first year (percentage)										3.00%
Loan prepayment fees for second year (percentage)										2.00%
Loan prepayment fees for third year (percentage)										1.00%
Term of loan										60 months
Term of interest payable (in months)										24 months
Administrative fee payable on term loan as a percentage										0.25%
Final payment of administrative fee payable on term loan as a percentage										4.00%
Debt instrument amount withdrawn									$ 5,000,000.0
Debt instrument scheduled commitment extended termination date									Jun. 30, 2019
Debt instrument remaining unfunded commitment amount									$ 15,000,000.0
Debt instrument increased commitment amount					$ 25,000,000		$ 500,000
Debt discount costs					$ 1,600,000		$ 1,500,000
Prior Term Loan | 90-day LIBOR | Term Loan Facility
Debt Instrument [Line Items]
Interest rate determination basis												90-day LIBOR
Variable rate (as a percent)					6.75%	5.50%	5.50%	6.75%		6.75%
Senior Secured Credit Agreement | Consolidated Senior Net Leverage Ratio is Greater Than or Equal to 3.00:1.00
Debt Instrument [Line Items]
Variable rate (as a percent)		3.25%
Senior Secured Credit Agreement | Consolidated Senior Net Leverage Ratio is Greater Than or Equal to 2.00:1.00 But Less Than 3.00:1.00
Debt Instrument [Line Items]
Variable rate (as a percent)		3.00%
Senior Secured Credit Agreement | Consolidated Senior Net Leverage Ratio is Greater Than or Equal to 1.00:1.00 But Less Than 2.00:1.00
Debt Instrument [Line Items]
Variable rate (as a percent)		2.75%
Senior Secured Credit Agreement | Consolidated Senior Net Leverage Ratio is Less Than 1.00:1.00
Debt Instrument [Line Items]
Variable rate (as a percent)		2.50%
Senior Secured Credit Agreement | Term loan
Debt Instrument [Line Items]
Term of loan		5 years
Credit facility borrowing capacity		$ 80,000,000
Senior Secured Credit Agreement | New Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility borrowing capacity		$ 40,000,000
Senior Secured Credit Agreement | New Credit Agreement
Debt Instrument [Line Items]
Unused commitment fee percentage per annum of average unused portion of the New Revolving Credit Facility											0.35%
Senior Secured Credit Agreement | New Credit Agreement | Consolidated Senior Net Leverage Ratio is Greater Than or Equal to 3.00:1.00
Debt Instrument [Line Items]
Unused commitment fee percentage per annum of average unused portion of the New Revolving Credit Facility		0.40%
Senior Secured Credit Agreement | New Credit Agreement | Consolidated Senior Net Leverage Ratio is Greater Than or Equal to 2.00:1.00 But Less Than 3.00:1.00
Debt Instrument [Line Items]
Unused commitment fee percentage per annum of average unused portion of the New Revolving Credit Facility		0.35%
Senior Secured Credit Agreement | New Credit Agreement | Consolidated Senior Net Leverage Ratio is Greater Than or Equal to 1.00:1.00 But Less Than 2.00:1.00
Debt Instrument [Line Items]
Unused commitment fee percentage per annum of average unused portion of the New Revolving Credit Facility		0.30%
Senior Secured Credit Agreement | New Credit Agreement | Consolidated Senior Net Leverage Ratio is Less Than 1.00:1.00
Debt Instrument [Line Items]
Unused commitment fee percentage per annum of average unused portion of the New Revolving Credit Facility		0.25%
Senior Secured Credit Agreement | New Credit Agreement | If all or Portion of Loans Under New Term Loan Facility are Prepaid
Debt Instrument [Line Items]
Unused commitment fee percentage per annum of average unused portion of the New Revolving Credit Facility		1.00%
Senior Secured Credit Agreement | 90-day LIBOR
Debt Instrument [Line Items]
Interest rate determination basis												90-day LIBOR
Variable rate (as a percent)											3.00%
Senior Secured Credit Agreement | 90-day LIBOR | Floor Rate
Debt Instrument [Line Items]
Variable rate (as a percent)		0.50%