Segment Information - Reported Revenue and Profit Before Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Revenue
Total revenue	$ 249,689		$ 243,830		$ 504,857		$ 482,976
Income (loss) before income taxes
Total income (loss) before income taxes	136		5,674		5,245		12,387
Private Client Division [Member]
Revenue
Total revenue	145,344	[1]	143,278	[1]	293,164	[1]	286,647	[1]
Income (loss) before income taxes
Total income (loss) before income taxes	7,560	[1]	15,698	[1]	17,868	[1]	33,025	[1]
Asset management fees	77.50%		77.50%		77.50%		77.50%
Asset Management [Member]
Revenue
Total revenue	25,032	[1]	22,006	[1]	49,642	[1]	42,962	[1]
Income (loss) before income taxes
Total income (loss) before income taxes	8,353	[1]	7,402	[1]	16,036	[1]	13,945	[1]
Asset management fees	22.50%		22.50%		22.50%		22.50%
Capital Markets [Member]
Revenue
Total revenue	72,217		67,904		150,098		133,035
Income (loss) before income taxes
Total income (loss) before income taxes	7,082		972		18,266		4,505
Commercial Mortgage Banking [Member]
Revenue
Total revenue	6,958		9,477		11,830		17,543
Income (loss) before income taxes
Total income (loss) before income taxes	3,605		2,276		5,454		5,154
Corporate and Other [Member]
Revenue
Total revenue	138		1,165		123		2,789
Income (loss) before income taxes
Total income (loss) before income taxes	$ (26,464)		$ (20,674)		$ (52,379)		$ (44,242)

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