Acquisitions (Narrative) (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 12 Months Ended | 12 Months Ended | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Mar. 31, 2012
|
Dec. 31, 2013
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Feb. 29, 2012
Acquisition Yokogawa-ORC [Member]
|
Dec. 31, 2013
Current Fiscal Period Acquisitions [Member]
|
Dec. 31, 2013
Prior Fiscal Periods Acquisitions [Member]
|
Dec. 31, 2012
Prior Fiscal Periods Acquisitions [Member]
|
Dec. 31, 2013
Risk and Insurance Services Segment [Member]
acquisition
|
Dec. 31, 2013
Consulting Segment [Member]
acquisition
|
Dec. 31, 2013
Maximum [Member]
|
Dec. 31, 2012
Maximum [Member]
|
Dec. 31, 2013
Minimum [Member]
|
Dec. 31, 2012
Minimum [Member]
|
Dec. 31, 2012
Marsh Insurance Group [Member]
acquisition
|
Dec. 31, 2012
Mercer Consulting Group [Member]
acquisition
|
|
Business Acquisition [Line Items] | ||||||||||||||||
Number of acquisitions made | 6 | 2 | 12 | 3 | ||||||||||||
Total Consideration | $ 178 | $ 360 | $ 178 | |||||||||||||
Cash | 139 | 252 | 139 | |||||||||||||
Estimated fair value of deferred/contingent consideration | 39 | 46 | 33 | 39 | ||||||||||||
Revenue target period (in years) | 4 years | 4 years | 2 years | 2 years | ||||||||||||
Deferred purchase consideration from prior years' acquisitions | 15 | 59 | 11 | 15 | ||||||||||||
Contingent payments for acquisitions | 17 | 30 | ||||||||||||||
Purchase of other intangibles | 2 | 3 | 4 | |||||||||||||
Business combination remaining interest acquired | 49.00% | |||||||||||||||
Cash held in escrow related to acquisition | 62 | 0 | 62 | 0 | ||||||||||||
Deferred purchase consideration | 59 | |||||||||||||||
Revenue related to acquisitions | 50 | |||||||||||||||
Net operating income related to acquisitions | $ 9 |