Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 425.3	$ 112.3
Debt securities available-for-sale, at fair value (amortized cost $517.3 million at September 30, 2020 and $557.3 million at December 31, 2019)	519.4	558.2
Accounts receivable	156.9	126.6
Inventories	20.6	17.3
Other current assets	34.7	16.6
Total current assets	1,156.9	831.0
Debt securities available-for-sale, at fair value (amortized cost $180.3 million at September 30, 2020 and $299.3 million at December 31, 2019)	181.4	299.7
Right-of-use assets	71.0	74.3
Equity securities	43.7	55.9
Property and equipment, net	43.0	41.9
Restricted cash	3.2	3.2
Other long-term assets	3.4	0.0
Total assets	1,502.6	1,306.0
Current liabilities:
Accounts payable and accrued liabilities	170.5	141.3
Convertible senior notes	425.0	408.8
Other current liabilities	15.5	15.2
Total current liabilities	611.0	565.3
Operating lease liabilities	83.0	86.7
Other long-term liabilities	4.3	17.1
Total liabilities	698.3	669.1
Stockholders’ equity:
Preferred stock, $0.001 par value; 5.0 shares authorized; no shares issued and outstanding at September 30, 2020 and December 31, 2019	0.0	0.0
Common stock, $0.001 par value; 220.0 shares authorized; issued and outstanding shares were 93.4 at September 30, 2020 and 92.3 at December 31, 2019	0.1	0.1
Additional paid-in capital	1,874.3	1,768.1
Accumulated other comprehensive income	3.2	1.4
Accumulated deficit	(1,073.3)	(1,132.7)
Total stockholders’ equity	804.3	636.9
Total liabilities and stockholders’ equity	$ 1,502.6	$ 1,306.0