Fair Value Measurements (Financial Instruments Measured at Fair Value on a Recurring Basis) (Detail) - USD ($) $ in Thousands	Mar. 31, 2017		Dec. 31, 2016		Jul. 01, 2016
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Royalty rights	$ 293,801	[1]	$ 402,318	[2]
Financial assets:
Assets, Fair Value	389,015		497,387
Warrants and Rights Outstanding	178		78
Financial liabilites:
Anniversary payment	88,493		88,001		$ 87,000
Business Combination, Contingent Consideration, Liability, Noncurrent	43,600		42,650
Liabilities, Fair Value Disclosure, Recurring	132,093		130,651
Money Market Funds [Member]
Financial assets:
Cash and Cash Equivalents, Fair Value	45		4
Certificates of Deposit [Member]
Financial assets:
Available for Sale Securities, Fair Value	75,000		75,000
Commercial Paper [Member]
Financial assets:
Available for Sale Securities, Fair Value	19,991		19,987
Fair Value Level 1 [Member]
Financial assets:
Assets, Fair Value	45		4
Fair Value Level 1 [Member] | Money Market Funds [Member]
Financial assets:
Cash and Cash Equivalents, Fair Value	45		4
Fair Value Level 1 [Member] | Certificates of Deposit [Member]
Financial assets:
Available for Sale Securities, Fair Value	0		0
Fair Value Level 1 [Member] | Commercial Paper [Member]
Financial assets:
Available for Sale Securities, Fair Value	0		0
Fair Value Level 2 [Member]
Financial assets:
Assets, Fair Value	95,169		95,065
Warrants and Rights Outstanding	178		78
Fair Value Level 2 [Member] | Money Market Funds [Member]
Financial assets:
Cash and Cash Equivalents, Fair Value	0		0
Fair Value Level 2 [Member] | Certificates of Deposit [Member]
Financial assets:
Available for Sale Securities, Fair Value	75,000		75,000
Fair Value Level 2 [Member] | Commercial Paper [Member]
Financial assets:
Available for Sale Securities, Fair Value	19,991		19,987
Fair Value Level 3 [Member]
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	132,093		130,651
Royalty rights	293,801		402,318
Financial assets:
Assets, Fair Value	293,801		402,318
Warrants and Rights Outstanding	0
Financial liabilites:
Anniversary payment	88,493		88,001
Business Combination, Contingent Consideration, Liability, Noncurrent	$ 43,600		$ 42,650

[1] unaudited

[2] Note 1