Consolidated Statements of Earnings - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue
Total revenues	$ 392,755	$ 408,897	$ 302,238
Costs and expenses
Cost of goods sold	16,660	15,356	15,215
Research and development	69,099	89,209	49,577
Selling, general and administrative	158,425	159,888	137,905
Total costs and expenses	244,184	264,453	202,697
Operating earnings	148,571	144,444	99,541
Other (expense) income
Interest expense	(22,707)	(18,111)	(1,568)
Interest income, net	21,623	13,843	2,645
Total	(1,084)	(4,268)	1,077
Earnings before income taxes	147,487	140,176	100,618
Income tax expense	34,431	29,183	43,334
Net earnings	$ 113,056	$ 110,993	$ 57,284
Earnings per share:
Basic (in dollars per share)	$ 2.16	$ 2.13	$ 1.13
Diluted (in dollars per share)	$ 2.10	$ 2.05	$ 1.08
Weighted-average shares outstanding
Basic (in shares)	52,412,181	51,989,824	50,756,603
Diluted (in shares)	53,816,754	54,098,872	53,301,150
Net product sales
Revenue
Total revenues	$ 383,400	$ 399,871	$ 294,097
Royalty revenue
Revenue
Total revenues	9,355	8,276	6,367
Licensing revenue
Revenue
Total revenues	$ 0	$ 750	$ 1,774