Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2020

Stockholders' Equity [Abstract]

Stock Option Activity

The following table summarizes the stock option activity under our stock plans for the year ended December 31, 2020 (in thousands, except per share and contractual life data):

	Number of Shares			Weighted Average Exercise Price Per Share		Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2019		11,001		$	51.48
Granted		2,764		$	59.89
Exercised		(1,069	)	$	40.88
Cancelled/forfeited/expired		(361	)	$	56.48
Outstanding at December 31, 2020		12,335		$	54.14		4.16	$	55,885
Exercisable at December 31, 2020		7,366		$	52.45		3.16	$	43,267

RSU Activity

The following table summarizes the RSU activity for the year ended December 31, 2020 (in thousands, except per share data):

	Number of Shares			Weighted Average Grant Date Fair Value Per Share
Non-vested at December 31, 2019		1,866		$	55.80
Granted		1,244		$	60.86
Vested		(602	)	$	53.68
Cancelled/forfeited		(134	)	$	58.96
Non-vested at December 31, 2020		2,374		$	58.81

Stock-Based Compensation Expense

The following table summarizes stock-based compensation expense for the years ended December 31, 2020, 2019 and 2018 (in thousands):

	Year Ended December 31,
	2020		2019		2018
Cost of products sold	$	1,991	$	438	$	160
Research, development and patent		115,584		95,348		76,557
Selling, general and administrative		112,542		50,788		54,595
Total	$	230,117	$	146,574	$	131,312

Stockholders' Equity [Abstract]

Weighted-Average Assumptions for Stock Options

Ionis Employee Stock Options:

	December 31,
	2020			2019			2018
Risk-free interest rate		1.5	%		2.3	%		2.4	%
Dividend yield		0.0	%		0.0	%		0.0	%
Volatility		58.6	%		60.3	%		63.0	%
Expected life	4.7 years			4.8 years			4.6 years

Ionis Board of Director Stock Options:

	December 31,
	2020			2019			2018
Risk-free interest rate		0.5	%		1.9	%		2.8	%
Dividend yield		0.0	%		0.0	%		0.0	%
Volatility		57.6	%		60.7	%		61.5	%
Expected life	6.7 years			6.6 years			6.6 years

Weighted-Average Assumptions for ESPP

Ionis ESPP:

	December 31,
	2020			2019			2018
Risk-free interest rate		0.8	%		2.4	%		1.8	%
Dividend yield		0.0	%		0.0	%		0.0	%
Volatility		47.9	%		45.6	%		47.3	%
Expected life	6 months			6 months			6 months

Akcea [Member]

Stockholders' Equity [Abstract]

Weighted-Average Assumptions for Stock Options

Akcea Employee Stock Options:

	December 31,
	2020			2019			2018
Risk-free interest rate		1.1	%		2.2	%		2.8	%
Dividend yield		0.0	%		0.0	%		0.0	%
Volatility		75.0	%		75.4	%		77.1	%
Expected life	6.08 years			6.09 years			6.08 years

Akcea Board of Director Stock Options:

	December 31,
	2020			2019			2018
Risk-free interest rate		0.8	%		1.8	%		2.9	%
Dividend yield		0.0	%		0.0	%		0.0	%
Volatility		75.3	%		73.8	%		78.2	%
Expected life	5.67 years			6.25 years			6.42 years

Weighted-Average Assumptions for ESPP

Akcea ESPP:

	December 31,
	2020			2019			2018
Risk-free interest rate		1.0	%		2.4	%		1.9	%
Dividend yield		0.0	%		0.0	%		0.0	%
Volatility		71.9	%		60.0	%		64.2	%
Expected life	6 months			6 months			6 months