Debt - Narrative (Details) $ / shares in Units, shares in Millions				1 Months Ended	3 Months Ended
	Oct. 02, 2018 USD ($) $ / shares shares	Jan. 07, 2018 USD ($) shares	Sep. 21, 2017 USD ($) shares	Feb. 28, 2015 USD ($) $ / shares shares	Sep. 30, 2018 USD ($) $ / shares	Sep. 30, 2017 USD ($)	Oct. 03, 2018 USD ($)	Jun. 30, 2018 USD ($) $ / shares
Debt Instrument [Line Items]
Common stock					$ 1,871,000			$ 1,868,000
Issuance of common shares for debt conversion					$ 0	$ 80,000,000
Common stock (in usd per share) | $ / shares					$ 0.01			$ 0.01
Amortization of debt issuance costs					$ 36,000	1,569,000
4.75% Convertible Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount				$ 100,000,000.0
Proceeds from debt, net of issuance costs				96,300,000
Payments of debt issuance costs				$ 3,700,000
Debt instrument, interest rate, stated percentage				4.75%
Debt instrument, interest rate, effective percentage					5.48%
Convertible preferred stock, shares issued upon conversion (in shares) | shares				19.6
Debt instrument, convertible, conversion ratio (in shares)					195.8336
Debt instrument, convertible, conversion price (in usd per share) | $ / shares				$ 5.11	$ 1,000
Issuance of common shares for debt conversion			$ 80,000,000
Debt conversion, converted instrument (in shares) | shares			16.8
Debt instrument convertible beneficial conversion feature (in shares) | shares			1.1
Induced conversion of convertible debt expense			$ 13,000,000
Interest expense, debt					$ 200,000	2,600,000
Amortization of debt issuance costs						1,600,000
Accelerated amortization of financing costs						$ 1,400,000
RPI Finance Trust | Funding agreement
Debt Instrument [Line Items]
Payments for future royalties		$ 175,000,000
Royalty purchase agreement arrangements consideration		250,000,000
Liability related to sale of future royalties		182,200,000						$ 202,000,000
Common stock		$ 67,800,000
Annual interest rate in calculating liability related to sale of future royalties		19.30%
Interest expense recognized					$ 9,800,000
Private placement | RPI Finance Trust | Funding agreement
Debt Instrument [Line Items]
Stock issued during period (in shares) | shares		4.4
Sale of stock, consideration received on transaction		$ 75,000,000
Subsequent event
Debt Instrument [Line Items]
Common stock (in usd per share) | $ / shares	$ 0.01
Subsequent event | 4.75% Convertible Senior Notes
Debt Instrument [Line Items]
Debt conversion, converted instrument (in shares) | shares	2.6
Induced conversion of convertible debt expense	$ 12,900,000
Senior notes							$ 7,100,000