New Accounting Standards (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Assets
Current deferred income taxes		$ 488
Noncurrent deferred income taxes		360
Noncurrent deferred income taxes	$ 859
Other assets	1,515	1,143
Total assets	36,851	33,956
Liabilities
Current deferred income taxes		206
Noncurrent deferred income taxes		1,543
Noncurrent deferred income taxes	1,897
Total liabilities	$ 47,751	45,432
Accounting Standards Update 2015-17 [Member] | Pro Forma [Member]
Assets
Noncurrent deferred income taxes		769
Other assets		1,143
Total assets		33,877
Liabilities
Noncurrent deferred income taxes		1,670
Total liabilities		$ 45,353