Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 783	$ 675	$ 578	$ 722	$ 693	$ 768	$ 791	$ 390	$ 2,758	$ 2,642	$ 1,819
TiO2
Disaggregation of Revenue [Line Items]
Net sales									2,176	2,049	1,230
Zircon
Disaggregation of Revenue [Line Items]
Net sales									283	290	293
Feedstock and other products
Disaggregation of Revenue [Line Items]
Net sales									299	303	259
Electrolytic
Disaggregation of Revenue [Line Items]
Net sales									0	0	37
North America
Disaggregation of Revenue [Line Items]
Net sales									794	696	649
South and Central America
Disaggregation of Revenue [Line Items]
Net sales									315	164	72
Europe, Middle-East and Africa
Disaggregation of Revenue [Line Items]
Net sales									879	954	541
Asia Pacific
Disaggregation of Revenue [Line Items]
Net sales									$ 770	$ 828	$ 557