Segment Operating Results (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Segment Reporting Information [Line Items]
Total Other Revenue, net	$ 2,863		$ (5,655)		$ (5,494)
Special Charges	170		662		3,894
Other Expenses	36,447	[1]	53,452	[1]	61,297	[1]
Investment Banking [Member]
Segment Reporting Information [Line Items]
Total Other Revenue, net	3,979	[2]	(3,019)	[2]	(2,473)	[2]
Interest expense on Senior Notes	4,386		4,312		4,238
Other Revenue, net, Changes in Tax Receivable Agreement	5,524
Amortization of LP Units and Certain Other Awards	17,817		18,601		21,328
Vesting of Event-based Awards	0		0		8,906
Acquisition Related Compensation Charges	15,923		28,163		14,618
Special Charges	0		662		3,894
Intangible Asset Amortization	0		3,348		6,845
Other Expenses	33,740	[1]	50,774	[1]	55,591	[1]
Investment Management [Member]
Segment Reporting Information [Line Items]
Total Other Revenue, net	(1,116)	[3]	(2,636)	[3]	(3,021)	[3]
Interest expense on Senior Notes	3,702		3,643		3,579
Other Revenue, net, Changes in Tax Receivable Agreement	1,381
Amortization of LP Units and Certain Other Awards	2,209		2,350		2,892
Vesting of Event-based Awards	0		0		2,483
Special Charges	170		0		0
Intangible Asset Amortization	328		328		331
Other Expenses	$ 2,707	[1]	$ 2,678	[1]	$ 5,706	[1]

[1] Other Expenses are as follows: For the Years Ended December 31, 2013 2012 2011Investment Banking Amortization of LP Units and Certain Other Awards$17,817 $18,601 $21,328Vesting of Event-based Awards— — 8,906Acquisition Related Compensation Charges15,923 28,163 14,618Special Charges— 662 3,894Intangible Asset Amortization— 3,348 6,845Total Investment Banking33,740 50,774 55,591Investment Management Amortization of LP Units and Certain Other Awards2,209 2,350 2,892Vesting of Event-based Awards— — 2,483Special Charges170 — —Intangible Asset Amortization328 328 331Total Investment Management2,707 2,678 5,706Total Other Expenses$36,447 $53,452 $61,297

[2] Investment Banking Other Revenue, net, includes interest expense on the Senior Notes of $4,386, $4,312 and $4,238 for the years ended December 31, 2013, 2012 and 2011, respectively, and changes in amounts due pursuant to the Company's tax receivable agreement of $5,524 for the year ended December 31, 2013.

[3] Investment Management Other Revenue, net, includes interest expense on the Senior Notes of $3,702, $3,643 and $3,579 for the years ended December 31, 2013, 2012 and 2011, respectively, and changes in amounts due pursuant to the Company's tax receivable agreement of $1,381 for the year ended December 31, 2013.