Quarterly Financial Data - Unaudited

12 Months Ended

Dec. 31, 2016

Quaterly Financial Data Unaudited [Abstract]

Quarterly Financial Information [Text Block]

Quarterly Financial Data—Unaudited

Dollars in millions

2016	Fourth		Third		Second		First
Revenues	$	5,310	$	5,167	$	4,585	$	4,767
Operating income	$	1,813	$	1,880	$	1,487	$	1,505
Net income	$	993	$	1,020	$	772	$	784

2015	Fourth		Third		Second		First
Revenues	$	5,396	$	5,600	$	5,369	$	5,602
Operating income	$	1,972	$	2,089	$	1,769	$	1,894
Net income	$	1,084	$	1,156	$	963	$	1,045