Segment Information - Reported Revenue and Profit Before Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Revenue
Total revenue	$ 244,679		$ 243,376		$ 749,536		$ 726,352
Income (loss) before income taxes
Total income (loss) before income taxes	10,896		8,163		16,141		20,550
Private Client Division [Member]
Revenue
Total revenue	142,606	[1]	144,316	[1]	435,770	[1]	430,963	[1]
Income (loss) before income taxes
Total income (loss) before income taxes	18,898	[1]	15,088	[1]	36,766	[1]	48,113	[1]
Asset management fees	77.50%		77.50%		77.50%		77.50%
Asset Management [Member]
Revenue
Total revenue	24,801	[1]	21,488	[1]	74,443	[1]	64,450	[1]
Income (loss) before income taxes
Total income (loss) before income taxes	8,264	[1]	6,387	[1]	24,300	[1]	20,332	[1]
Asset management fees	22.50%		22.50%		22.50%		22.50%
Capital Markets [Member]
Revenue
Total revenue	71,226		68,460		221,324		201,495
Income (loss) before income taxes
Total income (loss) before income taxes	5,699		4,301		23,965		8,806
Commercial Mortgage Banking [Member]
Revenue
Total revenue	6,349		9,314		18,179		26,857
Income (loss) before income taxes
Total income (loss) before income taxes	1,815		2,823		7,269		7,977
Corporate and Other [Member]
Revenue
Total revenue	(303)		(202)		(180)		2,587
Income (loss) before income taxes
Total income (loss) before income taxes	$ (23,780)		$ (20,436)		$ (76,159)		$ (64,678)

[1] Asset management fees are allocated 22.5% to the Asset Management and 77.5% to the Private Client segments.