CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 530,181	$ 683,287
Short-term investments	1,818,435	1,816,257
Contracts receivable	27,834	63,034
Inventories	23,722	18,180
Other current assets	131,015	139,839
Total current assets	2,531,187	2,720,597
Property, plant and equipment, net	172,618	153,651
Patents, net	27,700	25,674
Long-term deferred tax assets	305,980	305,557
Deposits and other assets	41,465	27,633
Total assets	3,078,950	3,233,112
Current liabilities:
Accounts payable	7,407	16,067
Accrued compensation	22,822	37,357
Accrued liabilities	67,802	66,769
Income taxes payable	27,943	32,514
Current portion of long-term obligations and other current liabilities	4,966	2,026
Current portion of deferred contract revenue	100,401	118,272
Total current liabilities	231,341	273,005
Long-term deferred contract revenue	448,576	490,060
Long-term obligations, less current portion	15,057	15,543
Long-term mortgage debt	59,948	59,913
Total liabilities	1,484,155	1,548,565
Stockholders' equity:
Common stock, $0.001 par value; 300,000,000 shares authorized, 139,489,405 and 140,339,615 shares issued and outstanding at June 30, 2020 (unaudited) and December 31, 2019, respectively	139	140
Additional paid-in capital	2,271,630	2,203,778
Accumulated other comprehensive loss	(16,440)	(25,290)
Accumulated deficit	(878,154)	(707,534)
Total Ionis stockholders' equity	1,377,175	1,471,094
Noncontrolling interest in Akcea Therapeutics, Inc.	217,620	213,453
Total stockholders' equity	1,594,795	1,684,547
Total liabilities and stockholders' equity	3,078,950	3,233,112
0.125 Percent Convertible Senior Notes [Member]
Current liabilities:
Convertible senior notes	445,150	434,711
1 Percent Convertible Senior Notes [Member]
Current liabilities:
Convertible senior notes	$ 284,083	$ 275,333