Business Acquisition, Consideration to be Transferred, Planned Acquisition

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- Definition

Business Acquisition, Percentage of Interests Acquired, Planned Acquisition

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- Definition

Equity Method Investment, Shares Owned

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- Definition

Other Shareholders, Ownership Percentage

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- Definition

Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

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No definition available.

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- Definition

Value of all classes of common stock held by shareholders. May be all or portion of the number of common shares authorized. These shares exclude common shares repurchased by the entity and held as treasury shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

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- Definition

This item represents the aggregate value of each identified investment accounted for under the equity method of accounting based on the quoted market price for those investments in common stock for which a quoted market price is available.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

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- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The cash inflow associated with the deconsolidation of a previously consolidated subsidiary or the sale of investment in consolidated subsidiaries (generally greater than 50 percent).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

Price of a single share of a number of saleable stocks of a company.

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No definition available.

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Fair Value Measurements (Equity Method Investments, Summarized Financial Information) (Details) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2017 R / shares	Dec. 31, 2016 USD ($)	Dec. 31, 2015 R / shares	Feb. 24, 2015 USD ($)
Schedule of Equity Method Investments [Line Items]
Carrying value of equity method investments	$ 405		$ 389
Gain from deconsolidation of subsidiary	11
Alexander Forbes Group Holdings Limited
Schedule of Equity Method Investments [Line Items]
Carrying value of equity method investments	$ 266
Equity investment shares owned by the Company (in shares) \| shares	443
Market value of equity method investment	$ 239
Share price \| (per share)	$ 7.50	R 6.87
Alexander Forbes Group Holdings Limited \| Mercer Consulting Group
Schedule of Equity Method Investments [Line Items]
Percentage of interest acquired				33.00%
Share price \| R / shares				R 7.50
Benefitfocus \| Mercer Consulting Group
Schedule of Equity Method Investments [Line Items]
Percentage of interest acquired					9.90%
Business acquisition, consideration to be transferred, planned acquisition					$ 75
Common stock, value, outstanding	$ 76
Marsh India Insurance Brokers Limited
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in equity method investment	26.00%
Local shareholders, ownership percentage	74.00%
Minimum \| Alexander Forbes Group Holdings Limited
Schedule of Equity Method Investments [Line Items]
Share price \| $ / shares	$ 5.26
Maximum \| Alexander Forbes Group Holdings Limited
Schedule of Equity Method Investments [Line Items]
Share price \| $ / shares	$ 7.95