Fair Value Measurements (Detail 4) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Rochdale Investment Management, LLC
Total realized/unrealized gains (losses):
Contingent consideration paid to shareholders			$ 17,400
Contingent Consideration Liability
Level 3 Liabilities Measured on a Recurring Basis
Balance, beginning of period	$ (34,983)	$ (49,900)
Total realized/unrealized gains (losses):
Included in earnings	(727)
Settlements		17,266
Other	(1,275)	(1,859)
Balance, end of period	$ (36,985)	(34,493)
Contingent Consideration Liability | Rochdale Investment Management, LLC
Total realized/unrealized gains (losses):
Business Acquisition Period of Additional Cash Consideration Payment	6 years
Low-end of the potential range of estimate of total consideration payment	$ 17,000
High-end of the potential range of estimate of total consideration payment	46,000
FDIC Clawback Liability
Level 3 Liabilities Measured on a Recurring Basis
Balance, beginning of period	(15,106)	(11,967)
Total realized/unrealized gains (losses):
Included in earnings	(1,502)	(2,557)
Balance, end of period	$ (16,608)	$ (14,524)