Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Millions	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010		Dec. 31, 2010
CURRENT ASSETS
Cash and cash equivalents	$ 317	$ 167	[1]	$ 316
Accounts receivable, net	1,049			839
Fiduciary assets	11,256			9,569
Deferred tax assets	32			36
Other current assets	327			340
Total current assets	12,981			11,100
NON-CURRENT ASSETS
Fixed assets, net	391			381
Goodwill	3,317			3,294
Other intangible assets, net	461			492
Investments in associates	186			161
Deferred tax assets	9			7
Pension benefits asset	231			179
Total other non-current assets	365			233
Total non-current assets	4,960			4,747
TOTAL ASSETS	17,941			15,847
CURRENT LIABILITIES
Fiduciary liabilities	11,256			9,569
Deferred revenue and accrued expenses	323			298
Income taxes payable	50			57
Short-term debt and current portion of long-term debt	114			110
Deferred tax liabilities	22			9
Total other current liabilities	318			266
Total current liabilities	12,083			10,309
NON-CURRENT LIABILITIES
Long-term debt	2,307			2,157
Liability for pension benefits	150			164
Deferred tax liabilities	111			83
Provisions for liabilities	184			179
Total other non-current liabilities	367			347
Total non-current liabilities	3,119			2,930
Total Liabilities	15,202			13,239
COMMITMENTS AND CONTINGENCIES
EQUITY
Ordinary shares, $0.000115 nominal value; Authorized: 4,000,000,000; Issued 172,949,656 shares in 2011 and 170,883,865 shares in 2010 Ordinary shares, EURO 1 nominal value; Authorized: 40,000; Issued 40,000 shares in 2011 and 2010	0			0
Preference shares, $0.000115 nominal value; Authorized:1,000,000,000; Issued nil shares in 2011 and 2010	0			0
Additional paid-in capital	1,033			985
Retained earnings	2,165			2,136
Accumulated other comprehensive loss, net of tax	(488)			(541)
Treasury shares, at cost, 46,408 shares, $0.000115 nominal value, in 2011 and 2010 and 40,000 shares, EURO 1 nominal value, in 2011 and 2010	(3)			(3)
Total Willis Group Holdings stockholder's equity	2,707			2,577
Noncontrolling interests	32			31
Total equity	2,739	2,429		2,608
TOTAL LIABILITIES AND EQUITY	$ 17,941			$ 15,847

[1] The 2010 Unaudited Condensed Consolidated Statement of Cash Flows has been recast to conform to the new balance sheet presentation. See Note 2 - Basis of Presentation and Significant Accounting Policies for details.