CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Total revenues	$ 120,282	$ 251,453	$ 141,102
Operating costs and expenses:
Cost of material sales	11,347	6,337	5,366
Amortization of intangibles	16,864	15,792	12,120
Research and development	55,908	27,863	26,887
General and administrative	41,884	37,734	28,653
Total operating costs and expenses	126,003	87,726	73,026
Gain from sale of Promacta license	812,797	0	0
Income from operations	807,076	163,727	68,076
Other income (expense):
Gain (loss) from Viking	2,888	50,187	(2,048)
Interest income	28,430	13,999	2,060
Interest expense	(35,745)	(48,276)	(13,460)
Other income (expense), net	(6,010)	(6,307)	2,603
Total other income (expense), net	(10,437)	9,603	(10,845)
Income before income tax expense	796,639	173,330	57,231
Income tax expense	(167,337)	(30,009)	(44,675)
Net income	$ 629,302	$ 143,321	$ 12,556
Earnings Per Share [Abstract]
Basic net income per share (USD per share)	$ 33.13	$ 6.77	$ 0.60
Shares used in basic per share calculation (shares)	18,995	21,160	21,032
Diluted net income per share (USD per share)	$ 31.85	$ 5.96	$ 0.53
Shares used in diluted per share calculation (shares)	19,757	24,067	23,481
Royalties
Revenues:
Total revenues	$ 46,976	$ 128,556	$ 88,685
Material sales
Revenues:
Total revenues	31,489	29,123	22,070
License fees, milestones and other revenues
Revenues:
Total revenues	$ 41,817	$ 93,774	$ 30,347