Intangible Assets Including Goodwill - Intangible Assets by Class (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Intangible asset balances by major asset class:
Gross Carrying Amount	$ 8,447	$ 6,543
Accumulated Amortization	(3,566)	(3,057)
Net Carrying Amount	4,881	3,487
Capitalized software
Intangible asset balances by major asset class:
Gross Carrying Amount	1,512	1,348
Accumulated Amortization	(630)	(581)
Net Carrying Amount	882	767
Client relationships
Intangible asset balances by major asset class:
Gross Carrying Amount	2,831	1,856
Accumulated Amortization	(1,163)	(927)
Net Carrying Amount	1,668	929
Completed technology
Intangible asset balances by major asset class:
Gross Carrying Amount	3,336	2,960
Accumulated Amortization	(1,577)	(1,397)
Net Carrying Amount	1,759	1,563
Patents/trademarks
Intangible asset balances by major asset class:
Gross Carrying Amount	723	335
Accumulated Amortization	(183)	(142)
Net Carrying Amount	540	193
Other intangible assets
Intangible asset balances by major asset class:
Gross Carrying Amount	46	44
Accumulated Amortization	(14)	(10)
Net Carrying Amount	$ 32	$ 35