ÐÇ¿Õ´«Ã½

Annual report pursuant to Section 13 and 15(d)

STOCK COMPENSATION PLANS - Narrative (Details)

v3.20.4
STOCK COMPENSATION PLANS - Narrative (Details)
12 Months Ended
Mar. 13, 2020
Dec. 31, 2020
shares
Dec. 31, 2019
shares
Dec. 31, 2018
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý
Granted shares Ìý 2,010,277 0 0
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Ìý 4,900,000 Ìý Ìý
AK Steel [Member] Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Ìý 5,700,000 Ìý Ìý
Business Acquisition, Shares Exchange Ratio 0.400 Ìý Ìý Ìý
Granted shares Ìý 2,000,000.0 Ìý Ìý
Performance Shares [Member] Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý
Granted shares Ìý 2,510,853 572,104 675,599
Performance Shares [Member] | AK Steel [Member] Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý
Granted shares Ìý 500,000 Ìý Ìý
Restricted Stock Units (RSUs) [Member] Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý
Granted shares Ìý 1,160,928 572,104 685,599
Restricted Stock Units (RSUs) [Member] | AK Steel [Member] Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý
Granted shares Ìý 300,000 Ìý Ìý
Long-term Performance Plan | AK Steel [Member] Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý
Granted shares Ìý 1,000,000.0 Ìý Ìý
Restricted Stock [Member] | AK Steel [Member] Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý
Granted shares Ìý 200,000 Ìý Ìý