Net Sales - Summary of Disaggregation of Net Sales by Geographical Region and Segment and Product Group (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended	9 Months Ended
	Mar. 31, 2025	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2024	Sep. 30, 2024
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	$ 1,368	$ 1,508	$ 1,554	$ 1,362	$ 2,915	$ 4,423
Other Non-Reportable Segment [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	11			14
Transferred at a Point in Time [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	1,368			1,362
Transferred at a Point in Time [Member] \| Titanium Technologies [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	597			591
Transferred at a Point in Time [Member] \| Thermal & Specialized Solutions [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	466			454
Transferred at a Point in Time [Member] \| Advanced Performance Materials [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	294			303
Transferred at a Point in Time [Member] \| Other Non-Reportable Segment [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	11			14
Transferred at a Point in Time [Member] \| North America [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	619			650
Transferred at a Point in Time [Member] \| North America [Member] \| Titanium Technologies [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	267			246
Transferred at a Point in Time [Member] \| North America [Member] \| Thermal & Specialized Solutions [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	233			271
Transferred at a Point in Time [Member] \| North America [Member] \| Advanced Performance Materials [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	111			124
Transferred at a Point in Time [Member] \| North America [Member] \| Other Non-Reportable Segment [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	8			9
Transferred at a Point in Time [Member] \| Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	275			294
Transferred at a Point in Time [Member] \| Asia Pacific [Member] \| Titanium Technologies [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	105			147
Transferred at a Point in Time [Member] \| Asia Pacific [Member] \| Thermal & Specialized Solutions [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	53			39
Transferred at a Point in Time [Member] \| Asia Pacific [Member] \| Advanced Performance Materials [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	115			105
Transferred at a Point in Time [Member] \| Asia Pacific [Member] \| Other Non-Reportable Segment [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	2			3
Transferred at a Point in Time [Member] \| Europe, the Middle East, and Africa [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	297			281
Transferred at a Point in Time [Member] \| Europe, the Middle East, and Africa [Member] \| Titanium Technologies [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	142			124
Transferred at a Point in Time [Member] \| Europe, the Middle East, and Africa [Member] \| Thermal & Specialized Solutions [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	98			92
Transferred at a Point in Time [Member] \| Europe, the Middle East, and Africa [Member] \| Advanced Performance Materials [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	56			63
Transferred at a Point in Time [Member] \| Europe, the Middle East, and Africa [Member] \| Other Non-Reportable Segment [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	1			2
Transferred at a Point in Time [Member] \| Latin America [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	177			137
Transferred at a Point in Time [Member] \| Latin America [Member] \| Titanium Technologies [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	83			74
Transferred at a Point in Time [Member] \| Latin America [Member] \| Thermal & Specialized Solutions [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	82			52
Transferred at a Point in Time [Member] \| Latin America [Member] \| Advanced Performance Materials [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	12			11
Transferred at a Point in Time [Member] \| Latin America [Member] \| Other Non-Reportable Segment [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	0			0
Transferred at a Point in Time [Member] \| Titanium Dioxide and Other Minerals [Member] \| Titanium Technologies [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	597			591
Transferred at a Point in Time [Member] \| Opteon Refrigerants [Member] \| Thermal & Specialized Solutions [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	279			200
Transferred at a Point in Time [Member] \| Freon Refrigerants [Member] \| Thermal & Specialized Solutions [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	97			173
Transferred at a Point in Time [Member] \| Foam, Propellants, and Other [Member] \| Thermal & Specialized Solutions [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	90			81
Transferred at a Point in Time [Member] \| Advanced Materials [Member] \| Advanced Performance Materials [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	178			190
Transferred at a Point in Time [Member] \| Performance Solutions [Member] \| Advanced Performance Materials [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	116			113
Transferred at a Point in Time [Member] \| Performance Chemicals and Intermediates [Member] \| Other Non-Reportable Segment [Member]
Disaggregation Of Revenue [Line Items]
Disaggregation of Net Sales	$ 11			$ 14