Intangible Assets and Goodwill (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Intangible assets
Finite-Lived Intangible Assets, Accumulated Amortization	$ 1,878		$ 1,878		$ 1,717
Weighted Amortizable Life (in years)			14 years		14 years
Finite-Lived Intangible Assets, Gross	4,110		$ 4,110		$ 4,066
Net	2,232		2,232		2,349
Intangible assets	2,232		2,232		2,349
Amortization expense	80	$ 82	159	$ 164
Remaining six months of 2017	160		160
2018	315		315
2019	310		310
2020	298		298
2021	281		281
Thereafter	868		868
Customer Relationships
Intangible assets
Finite-Lived Intangible Assets, Accumulated Amortization	1,026		$ 1,026		$ 934
Weighted Amortizable Life (in years)			15 years		15 years
Finite-Lived Intangible Assets, Gross	2,407		$ 2,407		$ 2,378
Net	1,381		1,381		1,444
Intellectual Property
Intangible assets
Finite-Lived Intangible Assets, Accumulated Amortization	769		$ 769		$ 706
Weighted Amortizable Life (in years)			11 years		11 years
Finite-Lived Intangible Assets, Gross	1,515		$ 1,515		$ 1,496
Net	746		746		790
Other
Intangible assets
Finite-Lived Intangible Assets, Accumulated Amortization	83		$ 83		$ 77
Weighted Amortizable Life (in years)			13 years		14 years
Finite-Lived Intangible Assets, Gross	188		$ 188		$ 192
Net	$ 105		$ 105		$ 115