Consolidated Statements of Earnings - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue
Total revenue	$ 408,897	$ 302,238	$ 215,003
Costs and expenses
Cost of product sales	15,356	15,215	11,986
Research and development	89,209	49,577	42,791
Selling, general and administrative	159,888	137,905	106,010
Total costs and expenses	264,453	202,697	160,787
Operating earnings	144,444	99,541	54,216
Other income (expense)
Interest income	13,843	2,864	1,467
Interest expense	(13,840)	(134)	(543)
Interest expense on non-recourse liability related to sale of future royalties	(4,271)	(1,434)	(4,548)
Changes in fair value of derivative liabilities		76	448
Loss on extinguishment of debt		(295)	(671)
Total other income (expense)	(4,268)	1,077	(3,847)
Earnings before income taxes	140,176	100,618	50,369
Income tax expense (benefit)	29,183	43,334	(40,852)
Net earnings	$ 110,993	$ 57,284	$ 91,221
Earnings per share:
Basic (in dollars per share)	$ 2.13	$ 1.13	$ 1.84
Diluted (in dollars per share)	$ 2.05	$ 1.08	$ 1.76
Weighted-average shares outstanding:
Basic (in shares)	51,989,824	50,756,603	49,472,434
Diluted (in shares)	54,098,872	53,301,150	51,708,983
Product
Revenue
Total revenue	$ 399,871	$ 294,097	$ 210,078
Royalty
Revenue
Total revenue	8,276	6,367	4,686
Licensing
Revenue
Total revenue	$ 750	$ 1,774	$ 239