Intangible Assets and Goodwill - Summary of Indefinite-lived Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Acquired Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible asset, Carrying Amount	$ 644,299	$ 644,299
MDV3800 [Member]
Acquired Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible asset, Carrying Amount	573,299	573,299
MDV9300 [Member]
Acquired Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible asset, Carrying Amount	$ 71,000	$ 71,000