Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Schedule of Future Minimum Lease Payments for Capital and Operating Leases [Table Text Block]

Future minimum lease payments as of December 31, 2017, are summarized as follows (in millions):

December 31,	Capital Leases			Operating Leases		a
2018	$	75		$	458
2019	71			452
2020	69			453
2021	200			378
2022	35			294
Thereafter	129			984
Total	579			$	3,019
Less amount representing interest	(113		)
Present value of minimum lease payments	$	466

^a Excludes leases having non-cancelable lease terms of less than one year and per diem leases. Minimum lease payments have not been reduced by minimum sublease rentals of $137 million due under future non-cancelable subleases.

Schedule of Loss Contingencies by Contingency

The following table summarizes the activity in the Company’s accrued obligations for asbestos and other personal injury matters (in millions):

	Year Ended			Year Ended			Year Ended
	December 31, 2017			December 31, 2016			December 31, 2015
Beginning balance	$	367		$	375		$	375
Accruals / changes in estimates	(1		)	80			81
Payments	(59		)	(88		)	(81		)
Ending balance	$	307		$	367		$	375

Accrued Obligations for Environmental Matters

The following table summarizes the activity in the Company’s accrued obligations for environmental matters (in millions):

	Year Ended			Year Ended			Year Ended
	December 31, 2017			December 31, 2016			December 31, 2015
Beginning balance	$	342		$	369		$	404
Accruals / changes in estimates	5			5			4
Payments	(30		)	(32		)	(39		)
Ending balance	$	317		$	342		$	369