v2.4.0.6

Acquisitions and Dispositions (Details 4) (USD $) In Millions, except Per Share data, unless otherwise specified | 3 Months Ended | 12 Months Ended | 15 Months Ended
--- | --- | --- | ---
Dec. 31, 2011 | Sep. 30, 2011 | Jun. 30, 2011 | Mar. 31, 2011 | Dec. 31, 2010 | Sep. 30, 2010 | Jun. 30, 2010 | Mar. 31, 2010 | Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009 | Dec. 31, 2010 Hewitt Associates, Inc (Hewitt) | Dec. 31, 2009 Hewitt Associates, Inc (Hewitt) | Dec. 31, 2011 Hewitt Associates, Inc (Hewitt)
Operating income loss |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue | $ 2,994 | $ 2,723 | $ 2,811 | $ 2,759 | $ 2,909 | $ 1,801 | $ 1,898 | $ 1,904 | $ 11,287 | $ 8,512 | $ 7,595 |  |  | $ 791
Operating Income | 435 | 341 | 434 | 396 | 422 | 263 | 268 | 273 | 1,606 | 1,226 | 1,021 |  |  | 23
Amortization expense on intangible assets |  |  |  |  |  |  |  |  | 362 | 154 | 93 |  |  | 37
Acquisition and transaction costs, pre-tax |  |  |  |  |  |  |  |  |  |  |  |  |  | 18
Restructuring expenses, pre-tax |  |  |  |  |  |  |  |  |  |  |  |  |  | 52
Pro Forma Impact of the Transaction |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue |  |  |  |  |  |  |  |  |  |  |  | 10,831 | 10,669 |
Net income attributable to Aon stockholders |  |  |  |  |  |  |  |  |  |  |  | 736 | 758 |
Earnings per Share: |  |  |  |  |  |  |  |  |  |  |  |  |  |
Basic (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  | $ 2.17 | $ 2.20 |
Diluted (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  | $ 2.14 | $ 2.15 |
Elimination of Hewitt's historical intangible asset amortization expense |  |  |  |  |  |  |  |  |  |  |  | 16 | 20 |
Additional amortization expense related to the fair value of intangible assets acquired |  |  |  |  |  |  |  |  |  |  |  | 293 | 218 |
Additional interest expense associated with the incremental debt issued by the entity to partially finance the acquisition |  |  |  |  |  |  |  |  |  |  |  | 43 | 77 |
Elimination of deferred revenues |  |  |  |  |  |  |  |  |  |  |  | 21 | 28 |
Elimination of deferred costs |  |  |  |  |  |  |  |  |  |  |  | 16 | 22 |
Additional expense related to unfavorable lease obligations |  |  |  |  |  |  |  |  |  |  |  | 15 | 15 |
Elimination of Hewitt's equity based compensation expense |  |  |  |  |  |  |  |  |  |  |  | 46 | 54 |
Elimination of acquisition related costs |  |  |  |  |  |  |  |  |  |  |  | $ 49 |  |
Combined statutory federal and state tax rate |  |  |  |  |  |  |  |  |  |  |  | 38.00% | 38.00% |

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- Definition The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(2)-(3) -URI http://asc.fasb.org/extlink&oid=6909870&loc=d3e1392-128463 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 54 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 55 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph r(2, 3) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
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- Definition This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 59 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 23 -URI http://asc.fasb.org/extlink&oid=6909708&loc=d3e1043-128460 + Details
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