Long-term Debt - Additional Information (Detail) $ / shares in Units, shares in Millions	1 Months Ended		3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 31, 2015 USD ($) Tranche	Jun. 30, 2014 USD ($) $ / shares shares	Jun. 30, 2016 USD ($) $ / shares	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) $ / shares	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) $ / shares	May 09, 2016 USD ($)	Jun. 11, 2014 $ / shares
PDL BioPharma
Debt Instrument [Line Items]
Proceeds from collaborators	$ 50,000,000				$ 3,900,000
Future maximum royalty payments, current year	20,000,000
Future maximum royalty payments, year two	20,000,000
Future maximum royalty payments, year three	$ 20,000,000
Percentage of royalty rate payable on net sales, current	2.50%
Percentage of royalty rate payable on net sales, year two	5.00%
Percentage of royalty rate payable on net sales, year four	6.50%
Internal rate of return (as percent)					10.00%
Interest expense, debt			$ 1,300,000		$ 2,300,000
Percentage of royalty rate payable on net sales, year three	5.00%
PDL BioPharma | Scenario 1
Debt Instrument [Line Items]
Contract amount	$ 50,000,000
Period to receive additional payment	1 year
PDL BioPharma | Scenario 2
Debt Instrument [Line Items]
Contract amount	$ 100,000,000
Amount of additional funding (up to)								$ 40,000,000
PDL BioPharma | Scenario 2 | Minimum
Debt Instrument [Line Items]
Period to receive additional payment	6 months
Number of tranches | Tranche	1
PDL BioPharma | Scenario 2 | Maximum
Debt Instrument [Line Items]
Period to receive additional payment	12 months
Number of tranches | Tranche	2
Convertible Note Warrant
Debt Instrument [Line Items]
Amount of debt issued		$ 200,000,000
Proceeds from issuance of warrants		$ 27,600,000
Underlying common stock shares covered in hedge (shares) | shares		21.5
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares		$ 12.00	$ 12.00		$ 12.00
Percentage Of Exercise Price Above Price Of Common Stock		70.00%
Put And Call Options | PDL BioPharma
Debt Instrument [Line Items]
Internal rate of return (as percent)	10.00%
Put And Call Options | PDL BioPharma | Period 1
Debt Instrument [Line Items]
Option exercise price as percentage of paid amount (as percent)			115.00%		115.00%
Put And Call Options | PDL BioPharma | Period 2
Debt Instrument [Line Items]
Option exercise price as percentage of paid amount (as percent)			120.00%		120.00%
Put And Call Options | PDL BioPharma | There After
Debt Instrument [Line Items]
Option exercise price as percentage of paid amount (as percent)			130.00%		130.00%
Convertible note hedge
Debt Instrument [Line Items]
Amount of debt issued		$ 200,000,000
Debt Instrument, Convertible, Conversion Price | $ / shares		$ 9.30
Adjustments to Additional Paid in Capital, Note Hedge Transactions		$ 43,200,000
Stock Issued During Period, Shares, Conversion of Convertible Securities | shares		21.5
Convertible notes
Debt Instrument [Line Items]
Amount of debt issued		$ 200,000,000.0	$ 200,000,000		$ 200,000,000		$ 200,000,000
Debt instrument, interest rate (as percent)		3.625%					3.625%
Proceeds from issuance of debt		$ 192,900,000
Debt instrument, fee amount		6,000,000
Expenses from debt issuance		$ 1,100,000
Debt Instrument, Date of First Required Payment							Dec. 15, 2014
Debt Instrument, Maturity Date							Jun. 15, 2019
Debt Instrument, Convertible, Conversion Price | $ / shares							$ 9.30
Debt Instrument, Convertible, Conversion Premium							32.50%
Sale of Stock, Price Per Share | $ / shares									$ 7.02
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed							100.00%
Interest Expenses Amortization Period							5 years
Debt instrument, term		5 years
Interest expense, debt			$ 4,062,000	$ 3,813,000	$ 8,071,000	$ 7,668,000
Remaining discount amortization period					35 months 15 days
Convertible notes | Convertible note hedge
Debt Instrument [Line Items]
Proceeds from issuance of debt		$ 43,200,000
Convertible notes | Liability Component
Debt Instrument [Line Items]
Expenses from debt issuance							$ 800,000
Effective interest rate (as percent)			9.625%		9.625%
Convertible notes | Equity Component [Member]
Debt Instrument [Line Items]
Expenses from debt issuance							$ 300,000
Default Event [Member] | Convertible Note [Member]
Debt Instrument [Line Items]
Debt Instrument Debt Covenants Debt Default Holder Percent To Declare All Notes Due Minimum							25.00%
Debt Instrument Consent Payment As Percentage Of Principal Amount							100.00%
Period To Cure Default							180 days