v2.4.0.6
ACQUISITIONS, GOODWILL AND INTANGIBLE ASSETS - Additional Information (Detail)
 3 Months Ended 6 Months Ended
Jun. 30, 2012
USD ($)
Jun. 30, 2011
USD ($)
Jun. 30, 2012
USD ($)
Segment
Jun. 30, 2011
USD ($)
Jan. 05, 2012
USD ($)
Jan. 05, 2012
EUR (€)
Dec. 31, 2011
USD ($)
Jun. 30, 2012
Private Equity
USD ($)
Jun. 30, 2012
Real Estate
USD ($)
Jun. 30, 2012
Hedge Fund Solutions
USD ($)
Jun. 30, 2012
Credit Businesses
USD ($)
Jun. 30, 2012
Financial Advisory
USD ($)
Business Acquisition [Line Items]                        
Purchase price in cash         $ 232,000,000 € 181,400,000            
Acquisition-related costs     2,100,000                  
Number of business segments     5                  
Goodwill, carrying value 1,703,602,000   1,703,602,000       1,703,602,000 694,500,000 421,700,000 172,100,000 346,400,000 68,900,000
Amortization expense 36,700,000 41,600,000 84,835,000 82,425,000                
Expected amortization of intangibles, 2012 139,300,000   139,300,000                  
Expected amortization of intangibles, 2013 88,200,000   88,200,000                  
Expected amortization of intangibles, 2014 83,300,000   83,300,000                  
Expected amortization of intangibles, 2015 77,100,000   77,100,000                  
Expected amortization of intangibles, 2016 $ 72,800,000   $ 72,800,000                  
Intangible assets expected to amortize over a weighted-average period     8 years 9 months 18 days