Supplemental Disclosures to the Consolidated Statements of Cash Flows (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Supplemental Disclosure to the Consolidate Statements of Cash Flows [Line Items]
Deferred and contingent consideration from prior years acquisition	$ 96	$ 42
Contingent consideration from prior year's acquisitions	43	12
Net charge for adjustments related to acquisition related accounts	5	42
Payment of contingent consideration	42	27
Non-cash issuance of common stock	71	68
Stock-based compensation expense, equity awards	66	49
Prior Fiscal Periods Acquisitions
Supplemental Disclosure to the Consolidate Statements of Cash Flows [Line Items]
Deferred purchase consideration from prior years' acquisitions	53	30
Contingent consideration from prior year's acquisitions	$ 85	39
Putnam
Supplemental Disclosure to the Consolidate Statements of Cash Flows [Line Items]
Reduction of net cash flow for operations by discontinued operations		$ 82