Financial Instruments - Additional Information (Detail) (USD $)	6 Months Ended					6 Months Ended		6 Months Ended				6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Auction Rate Securities Owned [Member]	Jun. 30, 2014 Deferred Compensation [Member] Corporate Equities Liabilities [Member]	Dec. 31, 2013 Deferred Compensation [Member] Corporate Equities Liabilities [Member]	Jun. 30, 2014 U.S. Treasury Notes [Member] contract	Jun. 30, 2014 Federal Funds Futures [Member]	Jun. 30, 2014 Mortgage Servicing Rights [Member]	Jun. 30, 2014 Senior Secured Notes [Member]	Apr. 12, 2011 Senior Secured Notes [Member]	Jun. 30, 2014 Auction Rate Securities [Member]	Jun. 30, 2014 Auction Rate Securities [Member] Maximum [Member]	Jun. 30, 2014 Fair Value, Valuation Scenario Two [Member] Auction Rate Securities [Member]	Jun. 30, 2014 Fair Value, Valuation Scenario One [Member] Auction Rate Securities [Member]	Jun. 30, 2014 Auction Rate Securities Purchase Commitment [Member]	Jun. 30, 2014 Auction Rate Securities Purchase Commitment [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of the corporate equities that are included in securities owned				$ 15,600,000	$ 15,300,000
Permanent and construction loans , discount rate								12.00%
Continuous prepayment rate used up to loans prepayment penalty rate hit 4%								0.00%
Continuous prepayment rate								4.00%
Continuous prepayment rate vast majority range minimum								10.00%
Continuous prepayment rate vast majority range maximum								15.00%
Continuous prepayment rate vast majority range average rate								12.00%
Estimated future cost to service loans on an annual basis per loan, average								1,250
Company purchased and holds auction rate securities											99,400,000
Commitment to purchase ARS from clients through 2016											20,200,000
Commitment to purchase ARS period maximum												2016
Sensitivity Analysis Of Fair Value Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities Change In Discount Rate													0.50%	0.25%
Decrease in fair value of ARS													2,100,000	1,000,000
Valuation adjustment (unrealized loss) for ARS	8,346,000		6,832,000												1,514,000	1,514,000
Interest rate									8.75%	8.75%
Fair value of the reverse repurchase agreements	250,000,000	184,000,000
Fair value of repurchase agreements		0
Loans held for sale period	60 days
Fair value of loan held for sale	15,806,000	75,989,000
Book value of loan held for sale	16,000,000
Number of open short contract						500
Open short contract, period						10 years
Interest Rate Fair Value Hedge Liability at Fair Value						188,000	43,000
Futures contracts used as economic hedge							$ 150,000
Open contracts for Federal Funds futures							839
Forward or delayed delivery of the underlying instrument with settlement	180 days