ÐÇ¿Õ´«Ã½

Annual report pursuant to Section 13 and 15(d)

STOCK COMPENSATION PLANS (Schedule of Compensation Costs) (Details)

v3.19.3.a.u2
STOCK COMPENSATION PLANS (Schedule of Compensation Costs) (Details) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended 12 Months Ended
Dec. 31, 2019
Sep. 30, 2019
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý
Share-based Payment Arrangement, Expense, Tax Benefit Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý $ (3.7) $ 0.0 $ 0.0
Share-based Payment Arrangement, Expense, after Tax Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý $ 13.9 $ 15.1 $ 18.2
Earnings (loss) per common share attributable to Cliffs common shareholders - basic: $ 0.23 $ 0.34 $ 0.59 $ (0.08) $ 2.06 $ 1.47 $ 0.55 $ (0.29) $ 1.06 $ 3.80 $ 1.28
Earnings (loss) per common share attributable to Cliffs common shareholders - diluted: $ 0.23 $ 0.33 $ 0.57 $ (0.08) $ 1.98 $ 1.41 $ 0.55 $ (0.29) 1.03 3.71 1.26
Share-based Payment Arrangement [Member] Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý
Earnings (loss) per common share attributable to Cliffs common shareholders - basic: Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý 0.05 0.05 0.06
Earnings (loss) per common share attributable to Cliffs common shareholders - diluted: Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý $ 0.05 $ 0.05 $ 0.06
Cost of goods sold and operating expenses [Member] Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý
Costs and Expenses Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý $ 2.0 $ 1.7 $ 1.9
Selling, General and Administrative Expenses [Member] Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý
Costs and Expenses Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý 15.6 13.4 16.3
Operating Income (Loss) [Member] Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý
Costs and Expenses Ìý Ìý Ìý Ìý Ìý Ìý Ìý Ìý $ 17.6 $ 15.1 $ 18.2