12. RESTRUCTURING, IMPAIRMENT AND PLANT CLOSING COSTS

As of  December 31, 2023, 2022 and 2021, accrued restructuring costs by type of cost consisted of the following (dollars in millions): 

Details with respect to our reserves for restructuring, impairment and plant closing costs by segment are provided below (dollars in millions):

Details with respect to cash and noncash restructuring charges from continuing operations for the years ended December 31, 2023, 2022 and 2021 are provided below (dollars in millions):

RESTRUCTURING ACTIVITIES

Beginning in the fourth quarter of 2022, we implemented a restructuring program to further realign our cost structure with additional restructuring in Europe. This program is associated with all of our segments and includes exiting and consolidating certain facilities, workforce relocation to lower cost locations and further personnel rationalization. In connection with this restructuring program, we recorded net restructuring expense of approximately $9 million for the year ended December 31, 2023, primarily related to workforce reductions and accelerated depreciation, partially offset by adjustments to restructuring reserves that are no longer required for certain workforce reductions. We recorded net restructuring expense of approximately $34 million for the year ended December 31, 2022, primarily related to workforce reductions. We expect to record further restructuring expenses of approximately $4 million through the first half of 2025.

Beginning in the first quarter of 2021, our Corporate function implemented a restructuring program to optimize our global approach to leveraging shared services capabilities. During the second quarter of 2022, this program was further expanded to include additional geographies. During the year ended December 31, 2023, we evaluated current developments of this program and related anticipated cash costs, and we recorded a net restructuring credit of approximately $6 million for the year ended December 31, 2023, primarily to adjust restructuring reserves that are no longer required for certain workforce reductions. During the years ended December 31, 2022 and 2021, we recorded approximately $15 million and $16 million, respectively, of net restructuring costs, primarily related to workforce reductions. We expect to record further restructuring expenses of approximately $1 million through the first half of 2024.

Beginning in the third quarter of 2020, our Polyurethanes segment implemented a restructuring program to optimize its downstream footprint. During the second quarter of 2022, this optimization program was further expanded to include the entire Polyurethanes business. In connection with this restructuring program, we recorded net restructuring expense of approximately $4 million, $10 million and $7 million for the years ended December 31, 2023, 2022 and 2021, respectively. During 2023 and 2022, this net expense primarily related to workforce reductions. During 2021, this net expense primarily related to workforce reductions and accelerated depreciation, partially offset by a gain on the sale of assets of approximately $3 million. We do not expect to record further significant restructuring expenses.

Beginning in the second quarter of 2020, our Advanced Materials segment implemented restructuring programs in connection with our 2020 acquisition of CVC Thermoset Specialties, the alignment of the segment’s commercial organization and optimization of the segment’s manufacturing processes. In connection with these restructuring programs, we recorded net restructuring expense of approximately $4 million, $8 million and $10 million for the years ended December 31, 2023, 2022 and 2021, respectively, primarily related to a site closure and accelerated depreciation. We expect to record further restructuring expenses of approximately $1 million through the first half of 2024.

Beginning in the third quarter of 2022, our Corporate function implemented restructuring programs to optimize our global approaches to leveraging managed services in various information technology functions and to align and optimize our supply chain and EHS processes and systems. In connection with these restructuring programs, we recorded net restructuring expense of approximately $19 million for the year ended December 31, 2022, primarily related to workforce reductions.