Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Condensed Consolidated Balance Sheets
Amortized cost	$ 388,768	$ 1,355,614
Allowance for credit losses	0	0
Allowance for doubtful accounts receivable	$ 1,339	$ 391
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	1,500,000,000	1,500,000,000
Common stock, shares issued	624,267,053	608,421,785
Common stock in treasury, shares	18,879,367	18,076,127