Long-term Debt - Additional Information (Detail) $ / shares in Units, shares in Millions	1 Months Ended		12 Months Ended
	Jul. 31, 2015 USD ($) Tranche	Jun. 30, 2014 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares	Dec. 31, 2014 USD ($)	Jun. 11, 2014 $ / shares
Debt Instrument [Line Items]
Net proceeds from issuance of convertible notes				$ 200,000,000
Proceeds from issuance of warrants		$ 27,580,000		27,580,000
Convertible Note Warrant
Debt Instrument [Line Items]
Debt instrument, principal amount		200,000,000
Proceeds from issuance of warrants		$ 27,600,000
Number of shares issued on warrant transactions | shares		21.5
Exercise price of shares issued on warrant transactions | $ / shares		$ 12.00
Percentage of exercise price above the last reported sale price of common stock		70.00%
PDL BioPharma
Debt Instrument [Line Items]
Proceeds from collaborators	$ 50,000,000		$ 1,400,000
Number of tranches | Tranche	2
Future Maximum Royalty Payments Receivable in 2015			$ 20,000,000
Royalty rate in 2015			2.50%
Future Maximum Royalty Payments Receivable in 2016			$ 20,000,000
Royalty rate in 2016			5.00%
Royalty rate in 2019			6.50%
Future Maximum Royalty Payments Receivable in 2017			$ 20,000,000
Internal rate of return			10.00%
Royalty rate in 2017			5.00%
Future Maximum Royalty Payments Receivable in 2018			$ 20,000,000
Royalty rate in 2018			5.00%
Royalty rate in year five			5.00%
Interest expense, debt			$ 2,600,000
PDL BioPharma | Put And Call Options
Debt Instrument [Line Items]
Internal rate of return	10.00%
PDL BioPharma | Put And Call Options | If exercised on or prior to the first anniversary of the closing date
Debt Instrument [Line Items]
Put and call options exercise price as percentage of amount paid			115.00%
PDL BioPharma | Put And Call Options | If exercised after the first anniversary but on or prior to the second anniversary of the closing date
Debt Instrument [Line Items]
Put and call options exercise price as percentage of amount paid			120.00%
PDL BioPharma | Put And Call Options | If exercised after the second anniversary of the closing date
Debt Instrument [Line Items]
Put and call options exercise price as percentage of amount paid			130.00%
PDL BioPharma | Maximum
Debt Instrument [Line Items]
Royalty Commitments, amount			$ 150,000,000
PDL BioPharma | To be received one year from the effective date
Debt Instrument [Line Items]
Franchise Revenue	$ 50,000,000
PDL BioPharma | To be received in one or two tranches between the six-month and twelve-month anniversary dates of the agreement
Debt Instrument [Line Items]
Franchise Revenue	$ 100,000,000
PDL BioPharma | Royalty rate for the remainder of the agreement if the Company draws down in excess of $150 million | Maximum
Debt Instrument [Line Items]
Royalty rate for excess withdrawal			7.50%
Convertible Note Hedge
Debt Instrument [Line Items]
Debt instrument, principal amount		$ 200,000,000
Exercise price of shares covered by note hedge transactions | $ / shares		$ 9.30
Number of shares issued on convertible note hedge transactions | shares		21.5
Convertible note hedge transactions, reduction to additional paid-in capital		$ 43,200,000
Convertible Note
Debt Instrument [Line Items]
Debt instrument conversion description			At any time prior to the close of business on the business day immediately preceding December 15, 2018, holders may convert their convertible notes at their option only under the following circumstances: during any calendar quarter commencing after the calendar quarter ending on December 31, 2014 (and only during such calendar quarter), if the last reported sale price of our common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130 percent of the conversion price, or approximately $12.00 per share, on each applicable trading day;during the five business day period after any five consecutive trading day period, or the measurement period, in which the trading price per $1,000 principal amount of the convertible notes for each trading day of the measurement period was less than 98 percent of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day; orupon the occurrence of specified corporate events.On or after December 15, 2018 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert all or any portion of their convertible notes, in multiples of $1,000 principal amount, at their option regardless of the foregoing circumstances.
Senior Notes
Debt Instrument [Line Items]
Debt instrument, principal amount		200,000,000	$ 200,000,000	200,000,000
Net proceeds from issuance of convertible notes		192,900,000
Fees related to debt		6,000,000
Cost and expense related to debt		1,100,000	$ 1,100,000
Debt instrument, interest rate			3.625%
Bank term loan, frequency of payments of principal and interest			Semi-annually
Debt instrument, interest payable date			--06-15
Debt instrument, interest payable date			--12-15
Debt instrument, interest payment start date			Dec. 15, 2014
Bank term loan, maturity date			Jun. 15, 2019
Initial conversion rate, shares per $1,000			0.10751%
Exercise price of shares covered by note hedge transactions | $ / shares			$ 9.30
Conversion premium percentage			32.50%
Sale price of common stock | $ / shares					$ 7.02
Repurchase price of principal amount			100.00%
Interest expenses amortization period			5 years
Interest expenses remaining amortization period			42 months 15 days
Expected life of debt			5 years
Interest expense, debt			$ 15,533,000	$ 8,016,000
Senior Notes | Convertible Note Hedge
Debt Instrument [Line Items]
Net proceeds from issuance of convertible notes		$ 43,200,000
Senior Notes | Equity Component
Debt Instrument [Line Items]
Cost and expense related to debt			300,000
Senior Notes | Liability Component
Debt Instrument [Line Items]
Cost and expense related to debt			$ 800,000
Debt instruments, effective interest rate			9.625%
Default Event | Convertible Note
Debt Instrument [Line Items]
Minimum percentage of principal amount of outstanding to declare			25.00%
Percentage of principal outstanding payable at event of default			100.00%
Period to resolve default of event			180 days