Condensed Consolidated Statements of Earnings - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues
Total revenues	$ 104,695	$ 99,538	$ 190,169	$ 189,967
Costs and expenses
Cost of product sales	4,044	3,683	7,728	6,961
Research and development	16,970	20,038	32,364	38,946
Selling, general and administrative	41,083	40,097	82,051	76,946
Total costs and expenses	62,097	63,818	122,143	122,853
Operating earnings	42,598	35,720	68,026	67,114
Other income (expenses), net	148	(1,864)	(1,041)	(2,076)
Earnings before income taxes	42,746	33,856	66,985	65,038
Income tax expense	10,019	3,119	15,918	7,949
Net earnings	$ 32,727	$ 30,737	$ 51,067	$ 57,089
Earnings per share
Basic (in dollars per share)	$ 0.62	$ 0.59	$ 0.98	$ 1.10
Diluted (in dollars per share)	$ 0.61	$ 0.57	$ 0.95	$ 1.06
Weighted-average shares outstanding
Basic (in shares)	52,385,590	51,919,894	52,361,149	51,729,243
Diluted (in shares)	53,912,977	54,203,308	53,947,834	54,021,941
Net product sales
Revenues
Total revenues	$ 102,358	$ 97,030	$ 185,457	$ 186,150
Royalty revenues
Revenues
Total revenues	2,337	1,758	4,712	3,067
Licensing revenues
Revenues
Total revenues	$ 0	$ 750	$ 0	$ 750