Goodwill And Other Intangible Assets (Schedule Of Changes In Goodwill By Segment) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Goodwill [Line Items]
Goodwill Gross, Beginning	$ 2,896,913	$ 2,392,307
Accumulated impairment losses	(1,068,506)	(1,068,506)
Goodwill, Net of impairment losses	1,828,407	1,323,801
Purchase accounting entries related to acquisitions	46,318	520,734
Foreign exchange movement	14,877	(16,128)
Goodwill Gross, Ending	2,958,108	2,896,913
Accumulated impairment losses	(1,068,506)	(1,068,506)
Goodwill, Net of impairment losses	1,889,602	1,828,407
Americas [Member]
Goodwill [Line Items]
Goodwill Gross, Beginning	1,641,748	1,642,323
Accumulated impairment losses	(798,290)	(798,290)
Goodwill, Net of impairment losses	843,458	844,033
Purchase accounting entries related to acquisitions	15,980
Foreign exchange movement	585	(575)
Goodwill Gross, Ending	1,658,313	1,641,748
Accumulated impairment losses	(798,290)	(798,290)
Goodwill, Net of impairment losses	860,023	843,458
EMEA [Member]
Goodwill [Line Items]
Goodwill Gross, Beginning	494,116	478,482
Accumulated impairment losses	(138,631)	(138,631)
Goodwill, Net of impairment losses	355,485	339,851
Purchase accounting entries related to acquisitions	31,440	24,659
Foreign exchange movement	8,140	(9,025)
Goodwill Gross, Ending	533,696	494,116
Accumulated impairment losses	(138,631)	(138,631)
Goodwill, Net of impairment losses	395,065	355,485
Asia Pacific [Member]
Goodwill [Line Items]
Goodwill Gross, Beginning	160,197	138,356
Accumulated impairment losses
Goodwill, Net of impairment losses	160,197	138,356
Purchase accounting entries related to acquisitions	1,175	23,344
Foreign exchange movement	(636)	(1,503)
Goodwill Gross, Ending	160,736	160,197
Accumulated impairment losses
Goodwill, Net of impairment losses	160,736	160,197
Global Investment Management [Member]
Goodwill [Line Items]
Goodwill Gross, Beginning	514,189	46,483
Accumulated impairment losses	(44,922)	(44,922)
Goodwill, Net of impairment losses	469,267	1,561
Purchase accounting entries related to acquisitions	(2,277)	472,731
Foreign exchange movement	6,788	(5,025)
Goodwill Gross, Ending	518,700	514,189
Accumulated impairment losses	(44,922)	(44,922)
Goodwill, Net of impairment losses	473,778	469,267
Development Services [Member]
Goodwill [Line Items]
Goodwill Gross, Beginning	86,663	86,663
Accumulated impairment losses	(86,663)	(86,663)
Goodwill, Net of impairment losses
Purchase accounting entries related to acquisitions
Foreign exchange movement
Goodwill Gross, Ending	86,663	86,663
Accumulated impairment losses	(86,663)	(86,663)
Goodwill, Net of impairment losses