ÐÇ¿Õ´«Ã½

Quarterly report pursuant to Section 13 or 15(d)

ASSET RETIREMENT OBLIGATIONS - Asset Retirement Obligation Disclosure (Details)

v3.20.2
ASSET RETIREMENT OBLIGATIONS - Asset Retirement Obligation Disclosure (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Asset Retirement Obligation [Roll Forward] Ìý Ìý
Asset retirement obligation at beginning of period $ 165.3 [1] $ 172.4
Increase from AK Steel acquisition 13.9 0.0
Accretion expense 4.9 5.1
Remediation payments (0.8) (0.4)
Asset retirement obligation at end of period $ 183.3 [1] $ 177.1
[1]
1 Includes $33.0 million and $22.0 million related to our active operations as of JuneÌý30, 2020 and DecemberÌý31, 2019, respectively.