Intangible Assets and Goodwill (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Intangible assets
Finite-Lived Intangible Assets, Accumulated Amortization	$ 1,789		$ 1,717
Weighted Amortizable Life (in years)	14 years		14 years
Finite-Lived Intangible Assets, Gross	$ 4,076		$ 4,066
Net	2,287		2,349
Intangible assets	2,287		2,349
Amortization expense	79	$ 82
Remaining Nine Months of 2017	237
2018	311
2019	305
2020	295
2021	277
Thereafter	862
Customer Relationships
Intangible assets
Finite-Lived Intangible Assets, Accumulated Amortization	$ 978		$ 934
Weighted Amortizable Life (in years)	15 years		15 years
Finite-Lived Intangible Assets, Gross	$ 2,388		$ 2,378
Net	1,410		1,444
Intellectual Property
Intangible assets
Finite-Lived Intangible Assets, Accumulated Amortization	$ 729		$ 706
Weighted Amortizable Life (in years)	11 years		11 years
Finite-Lived Intangible Assets, Gross	$ 1,497		$ 1,496
Net	768		790
Other
Intangible assets
Finite-Lived Intangible Assets, Accumulated Amortization	$ 82		$ 77
Weighted Amortizable Life (in years)	13 years		14 years
Finite-Lived Intangible Assets, Gross	$ 191		$ 192
Net	$ 109		$ 115