Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Accounting Policies [Abstract]

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

The following table indicates the percentage of total revenues in excess of 10% with any single customer:

	Year Ended December 31,
	2017	2016	2015
Roche	38%	63%	42%
BMS	32%	—	—
Alexion	13%	—	—
Baxalta	7%	12%	7%
Lilly	—	6%	19%
AbbVie	—	4%	17%

We attribute revenues under collaborative agreements, including royalties, to the individual countries where the collaborator is headquartered. We attribute revenues from product sales to the individual countries to which the product is shipped. Worldwide revenues from external customers are summarized by geographic location in the following table (in thousands):

	Year Ended December 31,
	2017		2016		2015
United States	$	196,274	$	52,292	$	77,149
Switzerland	119,136		93,067		57,136
All other foreign	1,203		1,332		772
Total revenues	$	316,613	$	146,691	$	135,057

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

A reconciliation of the numerators and the denominators of the basic and diluted net income (loss) per common share computations is as follows (in thousands, except per share amounts):

	Year Ended December 31,
	2017		2016			2015
Numerator:
Net income (loss)	$	62,971	$	(103,023	)	$	(32,231	)
Denominator:
Weighted average common shares outstanding for basic net income (loss) per share	136,419		127,964			126,704
Net effect of dilutive common stock equivalents	2,649		—			—
Weighted average common shares outstanding for diluted net income (loss) per share	139,068		127,964			126,704
Net income (loss) per share:
Basic	$	0.46	$	(0.81	)	$	(0.25	)
Diluted	$	0.45	$	(0.81	)	$	(0.25	)