Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts receivable	$ 3	$ 2
Total assets	10,587	11,290
Total liabilities	$ 5,744	$ 4,839
Common stock, par value (per share)	$ 0.01	$ 0.01
Common stock, authorized shares	6,000,000,000	6,000,000,000
Common stock, issued shares	236,217,344	239,589,639
Common stock, outstanding shares	235,915,749	239,386,877
Consolidated VIEs [Member]
Total assets	$ 229	$ 242
Total liabilities	$ 213	$ 219