Intangible Assets Including Goodwill - Intangible Assets by Class (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Intangible asset balances by major asset class:
Gross Carrying Amount	$ 8,250	$ 8,466
Accumulated Amortization	(4,070)	(3,778)
Net Carrying Amount	4,179	4,688
Capitalized software
Intangible asset balances by major asset class:
Gross Carrying Amount	1,575	1,537
Accumulated Amortization	(719)	(661)
Net Carrying Amount	856	876
Client relationships
Intangible asset balances by major asset class:
Gross Carrying Amount	2,748	2,831
Accumulated Amortization	(1,350)	(1,228)
Net Carrying Amount	1,398	1,602
Completed technology
Intangible asset balances by major asset class:
Gross Carrying Amount	3,167	3,322
Accumulated Amortization	(1,743)	(1,668)
Net Carrying Amount	1,424	1,654
Patents/trademarks
Intangible asset balances by major asset class:
Gross Carrying Amount	708	730
Accumulated Amortization	(240)	(205)
Net Carrying Amount	468	525
Other intangible assets
Intangible asset balances by major asset class:
Gross Carrying Amount	52	46
Accumulated Amortization	(18)	(15)
Net Carrying Amount	$ 34	$ 31