CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Current investments, amortized cost	$ 223,545	$ 137,124
Current investment, allowance for credit loss	0	0
Accounts receivable, allowance for credit losses	730	776
Non-current investments, amortized cost	476,148	587,981
Non-current investments, allowance for credit losses	$ 0	$ 0
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock par value, in dollars per share	$ 0.002	$ 0.002
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock, shares issued (in shares)	172,631,000	175,481,000
Common stock, shares outstanding (in shares)	172,631,000	175,481,000