Cost Saving Initiatives - Schedule of Expenses and Cumulative Expenses Associated with Implementation of Cost Saving Initiatives (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2013 USD ($)
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	$ 64,703
Compensation and Benefits [Member]
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	51,399
Other [Member]
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	13,304
Operating Segments [Member] | Financial Advisory Segment [Member]
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	47,779
Operating Segments [Member] | Financial Advisory Segment [Member] | Compensation and Benefits [Member]
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	45,746
Operating Segments [Member] | Financial Advisory Segment [Member] | Other [Member]
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	2,033
Operating Segments [Member] | Asset Management Segment [Member]
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	235
Operating Segments [Member] | Asset Management Segment [Member] | Compensation and Benefits [Member]
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	236
Operating Segments [Member] | Asset Management Segment [Member] | Other [Member]
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	(1)
Corporate [Member]
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	16,689
Corporate [Member] | Compensation and Benefits [Member]
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	5,417
Corporate [Member] | Other [Member]
Restructuring and Related Cost [Abstract]
Cost Saving Initiatives	$ 11,272