Segment Information and Concentration of Business Risk (Tables)

12 Months Ended

Dec. 31, 2017

Segment Information and Concentration of Business Risk [Abstract]

Segment Information

2017	Ionis Core		Akcea Therapeutics			Elimination of Intercompany Activity			Total
Revenue:
Commercial revenue:
SPINRAZA royalties	$	112,540	$	—		$	—		$	112,540
Licensing and other royalty revenue		9,519		—			—			9,519
Total commercial revenue		122,059		—			—			122,059
R&D revenue under collaborative agreements		384,805		55,209			(54,407	)		385,607
Total segment revenue	$	506,864	$	55,209		$	(54,407	)	$	507,666
Total operating expenses	$	373,788	$	163,871		$	(54,527	)	$	483,132
Income (loss) from operations	$	133,076	$	(108,662	)	$	120		$	24,534

2016	Ionis Core		Akcea Therapeutics			Elimination of Intercompany Activity			Total
Revenue:
Commercial revenue:
SPINRAZA royalties	$	883	$	—		$	—		$	883
Licensing and other royalty revenue		19,839		—			—			19,839
Total commercial revenue		20,722		—			—			20,722
R&D revenue under collaborative agreements		338,546		—			(12,648	)		325,898
Total segment revenue	$	359,268	$	—		$	(12,648	)	$	346,620
Total operating expenses	$	322,192	$	83,512		$	(12,768	)	$	392,936
Income (loss) from operations	$	37,076	$	(83,512	)	$	120		$	(46,316	)

2015	Ionis Core			Akcea Therapeutics			Elimination of Intercompany Activity			Total
Revenue:
R&D revenue under collaborative agreements	$	284,015		$	—		$	(2,655	)	$	281,360
Licensing and other royalty revenue		2,343			—			—			2,343
Total segment revenue	$	286,358		$	—		$	(2,655	)	$	283,703
Total operating expenses	$	309,492		$	52,748		$	(2,775	)	$	359,465
Income (loss) from operations	$	(23,134	)	$	(52,748	)	$	120		$	(75,762	)

The following table shows our total assets by segment at December 31, 2017 and 2016 (in thousands), respectively.

Total Assets	Ionis Core		Akcea Therapeutics		Elimination of Intercompany Activity			Total
December 31, 2017	$	1,341,828	$	268,804	$	(288,608	)	$	1,322,024
December 31, 2016	$	1,067,770	$	10,684	$	(165,987	)	$	912,467

Revenue from Significant Partners

We have historically funded our operations from collaborations with corporate partners and a relatively small number of partners have accounted for a significant percentage of our revenue. Revenue from significant partners, which is defined as 10 percent or more of our total revenue, was as follows:

	2017			2016			2015
Partner A		51	%		60	%		37	%
Partner B		14	%		2	%		33	%
Partner C		10	%		2	%		11	%
Partner D		11	%		0	%		0	%
Partner E		3	%		19	%		2	%
Partner F		2	%		4	%		12	%