Long-term Debt and Interest Expense - Interest Costs (Details) - 0.250% convertible senior notes due 2025 - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Debt Instrument [Line Items]
Contractual coupon interest	$ 1	$ 1	$ 2	$ 3
Amortization of capitalized loan fees	1	1	3	4
Total interest expense on convertible notes	$ 2	$ 2	$ 5	$ 7