- Definition

The increases or decreases in lease payments that result from changes occurring after the inception of the lease in the factors (other than the passage of time) on which lease payments are based, except that any escalation of minimum lease payments relating to increases in construction or acquisition cost of the leased property or for increases in some measure of cost or value during the construction or preconstruction period, are excluded from contingent rentals. Contingent rentals also may include amounts for which the triggering events have not yet occurred or the specified targets for which have not yet been achieved (such as sales based percentage rent), but which events are considered probable of occurring or which specified targets are considered probable of being achieved.

+ References+ Details

Leases - Textuals (Details)	3 Months Ended		6 Months Ended		12 Months Ended	18 Months Ended
Leases - Textuals (Details)	Jun. 30, 2020 USD ($) leases	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) leases	Jun. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Lease Obligation, Assumed Amount Recoverable from Third Parties	$ 0		$ 0
Provision for North Goonyella equipment loss	$ 0	$ 0	$ 0	$ 24,700,000	$ 66,400,000
Number of Operating Leases with Contingent Rent Provisions \| leases	1		1
Operating Leases, Rent Expense, Contingent Rentals	$ 0	$ 0	$ 0	0
Minimum
Lessee, Lease, Description [Line Items]
Operating and Finance Leases Remaining Lease Term			1 year
Maximum
Lessee, Lease, Description [Line Items]
Operating and Finance Leases Remaining Lease Term			21 years 6 months
North Goonyella Mine
Lessee, Lease, Description [Line Items]
Provision for North Goonyella equipment loss				$ 24,700,000		$ 149,600,000