Quarterly Financial Data - Unaudited

12 Months Ended

Dec. 31, 2015

Quaterly Financial Data Unaudited [Abstract]

Quarterly Financial Information [Text Block]

Quarterly Financial Data—Unaudited

Dollars in millions

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

2014	Fourth		Third		Second		First
Revenues	$	6,176	$	5,881	$	5,735	$	5,447
Operating income	$	2,097	$	1,868	$	1,680	$	1,368
Net income	$	1,194	$	1,035	$	916	$	724