Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2019

Loss Contingencies [Line Items]

Remediation Cost Estimates

Our estimates regarding remediation costs to be incurred were as follows at December 31: 

(In millions, except percentages)	2019			2018
Total remediation costs—undiscounted	$	188		$	193
Weighted-average discount rate	5.1		%	5.1		%
Total remediation costs—discounted	$	124		$	128
Recoverable portion	81			82

Schedule of Environmental Remediation Costs

Environmental remediation costs expected to be incurred are:

(In millions)
2020	$	25
2021	16
2022	13
2023	11
2024	11
Thereafter	112

Stated Values Outstanding, Guarantees, Letters of credit and Surety bonds

The stated values outstanding consisted of the following at December 31: 

(In millions)	2019		2018
Guarantees	$	219	$	201
Letters of credit	3,485		2,503
Surety bonds	83		166