Guarantees (Tables)

6 Months Ended

Jun. 30, 2018

Service and Product Warranties and Product Performance Guarantees [Abstract]

Product Warranty Disclosure [Table Text Block]

The changes in the carrying amount of service and product warranties and product performance guarantees for the six months ended June 30, 2018 and 2017 are as follows:

(dollars in millions)	2018			2017
Balance as of January 1	$	1,146		$	1,199
Warranties and performance guarantees issued	233			142
Settlements made	(200		)	(120		)
Other	(7		)	13
Balance as of June 30	$	1,172		$	1,234