Leases (Tables)

3 Months Ended

Mar. 31, 2021

The components of lease expense during the three months ended March 31, 2021 and 2020 were as follows:


	Three Months Ended March 31,
	2021		2020
	(Dollars in millions)
Operating lease cost:
Operating lease cost	$	6.0	$	8.6
Short-term lease cost	3.4		9.9
Variable lease cost	0.5		1.0
Sublease income	(0.5)		—
Total operating lease cost	$	9.4	$	19.5

Finance lease cost:
Amortization of right-of-use assets	$	0.6	$	3.4
Interest on lease liabilities	0.5		0.2
Total finance lease cost	$	1.1	$	3.6

Supplemental balance sheet information related to leases at March 31, 2021 and December 31, 2020 was as follows:


	March 31, 2021			December 31, 2020
	(Dollars in millions)
Operating leases:
Operating lease right-of-use assets	$	46.8		$	49.9

Accounts payable and accrued expenses	$	21.1		$	24.5
Operating lease liabilities, less current portion	37.5			42.1
Total operating lease liabilities	$	58.6		$	66.6

Finance leases:
Property, plant, equipment and mine development	$	13.8		$	20.4
Accumulated depreciation	(3.1)			(2.5)
Property, plant, equipment and mine development, net	$	10.7		$	17.9

Current portion of long-term debt	$	5.9		$	21.5
Long-term debt, less current portion	11.4			5.8
Total finance lease liabilities	$	17.3		$	27.3

Weighted average remaining lease term (years)
Operating leases	3.4
Finance leases	8.2

Weighted average discount rate
Operating leases	6.7		%
Finance leases	10.1		%

Supplemental cash flow information related to leases during the three months ended March 31, 2021 and 2020 was as follows:


	Three Months Ended March 31,
	2021		2020
	(Dollars in millions)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	$	8.3	$	12.8
Operating cash flows for finance leases	0.7		0.2
Financing cash flows for finance leases	1.3		5.8

Right-of-use assets obtained in exchange for lease obligations:
Operating leases	3.1		1.3
Finance leases	3.6		0.1

he contractual maturities of lease liabilities were as follows:

he contractual maturities of lease liabilities were as follows: