Goodwill and Other Intangible Assets, Net - Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Finite-Lived Intangible Assets
Accumulated Amortization	$ (232,209)	$ (219,026)	$ (208,700)
Gross Amount	788,510	952,323
Gross Impairment	(18,823)	(163,813)
Net Balance	537,478	569,484
IPR&D
Indefinite-lived Intangible Assets
Gross Amount	149,161	173,757
Reclassifications	(5,300)	0
Gross Impairment, Indefinite-lived intangible assets	(17,873)	(24,596)
Net Balance	125,988	149,161
Product licensing rights
Finite-Lived Intangible Assets
Gross Amount	607,889	747,106
Accumulated Amortization	(218,006)	(205,549)
Reclassifications	5,300	0
Gross Impairment - Finite-lived intangible assets	(950)	(139,217)
Net Balance	$ 394,233	$ 402,340
Wtd Avg Remaining Amortization Period (years)	9 years 7 months 6 days	9 years 9 months 18 days
Trademarks
Finite-Lived Intangible Assets
Gross Amount	$ 16,000	$ 16,000
Accumulated Amortization	(5,608)	(5,376)
Reclassifications	0	0
Gross Impairment - Finite-lived intangible assets	0	0
Net Balance	$ 10,392	$ 10,624
Wtd Avg Remaining Amortization Period (years)	17 years 8 months 12 days	17 years 9 months 18 days
Customer relationships
Finite-Lived Intangible Assets
Gross Amount	$ 4,225	$ 4,225
Accumulated Amortization	(2,123)	(2,058)
Reclassifications	0	0
Gross Impairment - Finite-lived intangible assets	0	0
Net Balance	$ 2,102	$ 2,167
Wtd Avg Remaining Amortization Period (years)	8 years 1 month 6 days	8 years 3 months 19 days
Other intangibles
Finite-Lived Intangible Assets
Gross Amount	$ 11,235	$ 11,235
Accumulated Amortization	(6,472)	(6,043)
Reclassifications	0	0
Gross Impairment - Finite-lived intangible assets	0	0
Net Balance	$ 4,763	$ 5,192
Wtd Avg Remaining Amortization Period (years)	5 years 7 months 6 days	5 years 8 months 12 days