LEASES: (Tables)

9 Months Ended

Sep. 30, 2020

LEASES:

Schedule of the operating lease expense recognized

The operating lease expense recognized in the nine months ended September 30, 2020 and 2019 was classified as follows (in millions):

Classification	2020		2019
Cost of sales (exclusive of depreciation, amortization and depletion)	$	86.4	$	86.8
Selling, general and administrative		0.2		0.1
Exploration		0.1		0.1
Total lease expense	$	86.7	$	87.0

Schedule of Maturities of lease liabilities

	Lease liabilities
Year	(in millions)
2020	$	28.9
2021		115.5
2022		112.6
2023		111.5
2024		103.6
After 2024		826.3
Total lease payments	$	1,298.4
Less: interest on lease liabilities		(303.7)
Present value of lease payments	$	994.7