CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 397,664	$ 683,287
Short-term investments	1,494,711	1,816,257
Contracts receivable	76,204	63,034
Inventories	21,965	18,180
Other current assets	140,163	139,839
Total current assets	2,130,707	2,720,597
Property, plant and equipment, net	181,077	153,651
Patents, net	27,937	25,674
Long-term deferred tax assets	0	305,557
Deposits and other assets	50,034	27,633
Total assets	2,389,755	3,233,112
Current liabilities:
Accounts payable	17,199	16,067
Accrued compensation	65,728	37,357
Accrued liabilities	90,161	66,769
Income taxes payable	1,324	32,514
1 percent convertible senior notes	293,161	0
Current portion of long-term obligations	7,301	2,026
Current portion of deferred contract revenue	108,376	118,272
Total current liabilities	583,250	273,005
Long-term deferred contract revenue	424,046	490,060
Long-term obligations, less current portion	23,409	15,543
Long-term mortgage debt	59,984	59,913
Total liabilities	1,546,408	1,548,565
Stockholders' equity:
Common stock, $0.001 par value; 300,000,000 shares authorized, 140,365,594 and 140,339,615 shares issued and outstanding at December 31, 2020 and December 31, 2019, respectively	140	140
Additional paid-in capital	2,113,646	2,203,778
Accumulated other comprehensive loss	(21,071)	(25,290)
Accumulated deficit	(1,249,368)	(707,534)
Total Ionis stockholders' equity	843,347	1,471,094
Noncontrolling interest in Akcea Therapeutics, Inc.	0	213,453
Total stockholders' equity	843,347	1,684,547
Total liabilities and stockholders' equity	2,389,755	3,233,112
0.125 Percent Convertible Senior Notes [Member]
Current liabilities:
Convertible senior notes	455,719	434,711
1 Percent Convertible Senior Notes [Member]
Current liabilities:
1 percent convertible senior notes	293,200
Convertible senior notes	$ 0	$ 275,333