Piper Sandler Companies (PIPR) 10-Q 1 May 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014	Apr. 17, 2014
Document and Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Trading Symbol	'PJC	'
Entity Registrant Name	'Piper Jaffray Companies	'
Entity Central Index Key	'0001230245	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	16,267,433

Consolidated_Statements_of_Fin

Consolidated Statements of Financial Condition (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets	'	'
Cash and cash equivalents	$34,835	$123,683
Cash and cash equivalents segregated for regulatory purposes	44,141	43,012
Receivables:	'	'
Customers	19,785	11,633
Brokers, dealers and clearing organizations	230,563	127,113
Securities purchased under agreements to resell	176,865	167,875
Financial instruments and other inventory positions owned	417,171	406,513
Financial instruments and other inventory positions owned and pledged as collateral	908,217	957,515
Total financial instruments and other inventory positions owned	1,325,388	1,364,028
Fixed assets (net of accumulated depreciation and amortization of $63,665 and $62,311, respectively)	15,310	16,114
Goodwill	210,634	210,634
Intangible assets (net of accumulated amortization of $34,187 and $31,869, respectively)	37,612	39,930
Investments	130,255	112,043
Other assets	91,864	102,092
Total assets	2,317,252	2,318,157
Liabilities and Shareholders’ Equity	'	'
Short-term financing	435,809	514,711
Variable rate senior notes	125,000	125,000
Payables:	'	'
Customers	40,218	33,109
Brokers, dealers and clearing organizations	110,980	27,722
Securities sold under agreements to repurchase	52,046	4,397
Financial instruments and other inventory positions sold, but not yet purchased	512,693	512,833
Accrued compensation	78,684	159,928
Other liabilities and accrued expenses	44,743	58,385
Total liabilities	1,400,173	1,436,085
Shareholders’ equity:	'	'
Common stock, $0.01 par value: Shares authorized: 100,000,000 at March 31, 2014 and December 31, 2013; Shares issued: 19,520,553 at March 31, 2014 and 19,537,127 at December 31, 2013; Shares outstanding: 14,915,556 at March 31, 2014 and 14,383,418 at December 31, 2013	195	195
Additional paid-in capital	738,391	740,321
Retained earnings	181,641	163,893
Less common stock held in treasury, at cost: 4,604,997 shares at March 31, 2014 and 5,153,709 shares at December 31, 2013	-153,720	-170,629
Accumulated other comprehensive income	947	896
Total common shareholders’ equity	767,454	734,676
Noncontrolling interests	149,625	147,396
Total shareholders’ equity	917,079	882,072
Total liabilities and shareholders’ equity	$2,317,252	$2,318,157

Consolidated_Statements_of_Fin1

Consolidated Statements of Financial Condition (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Accumulated depreciation and amortization on fixed assets	$63,665	$62,311
Accumulated amortization on intangible assets	$34,187	$31,869
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	19,520,553	19,537,127
Common stock, shares outstanding	14,915,556	14,383,418
Common stock held in treasury, shares	4,604,997	5,153,709

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Revenues:	'	'
Investment banking	$88,474	$40,821
Institutional brokerage	44,034	40,147
Asset management	20,959	18,456
Interest	13,659	10,823
Investment income	6,768	5,065
Total revenues	173,894	115,312
Interest expense	5,761	5,779
Net revenues	168,133	109,533
Non-interest expenses:	'	'
Compensation and benefits	100,489	66,105
Occupancy and equipment	6,778	5,817
Communications	5,955	5,232
Floor brokerage and clearance	1,834	2,150
Marketing and business development	5,526	4,980
Outside services	9,493	7,214
Intangible asset amortization expense	2,318	1,661
Other operating expenses	3,027	-1,794
Total non-interest expenses	135,420	91,365
Income from continuing operations before income tax expense	32,713	18,168
Income tax expense	9,827	5,600
Income from continuing operations	22,886	12,568
Discontinued operations:	'	'
Loss from discontinued operations, net of tax	0	-521
Net income/(loss)	22,886	12,047
Net income applicable to noncontrolling interests	5,138	1,901
Net income/(loss) applicable to Piper Jaffray Companies	17,748	10,146
Net income/(loss) applicable to Piper Jaffray Companies’ common shareholders	16,089	8,966
Amounts applicable to Piper Jaffray Companies	'	'
Net income/(loss) from continuing operations	17,748	10,667
Net loss from discontinued operations	$0	($521)
Earnings/(loss) per basic common share	'	'
Income from continuing operations	$1.10	$0.60
Loss from discontinued operations	$0	($0.03)
Earnings per basic common share	$1.10	$0.58
Earnings/(loss) per diluted common share	'	'
Income from continuing operations	$1.10	$0.60
Loss from discontinued operations	$0	($0.03)
Earnings per diluted common share	$1.10	$0.57
Weighted average number of common shares outstanding	'	'
Basic	14,612	15,582
Diluted	14,657	15,610

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]	'	'
Net income/(loss)	$22,886	$12,047
Other comprehensive income/(loss), net of tax:	'	'
Foreign currency translation adjustment	51	-148
Comprehensive income/(loss)	22,937	11,899
Comprehensive income applicable to noncontrolling interests	5,138	1,901
Comprehensive income/(loss) applicable to Piper Jaffray Companies	$17,799	$9,998

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Operating Activities:	'	'
Net income/(loss)	$22,886	$12,047
Adjustments to reconcile net income/(loss) to net cash provided by/(used in) operating activities:	'	'
Depreciation and amortization of fixed assets	1,418	1,426
Deferred income taxes	8,142	12,070
Share-based and deferred compensation	5,375	795
Amortization of intangible assets	2,318	1,661
Amortization of forgivable loans	1,327	1,725
Decrease/(increase) in operating assets:	'	'
Cash and cash equivalents segregated for regulatory purposes	-1,129	-14,005
Receivables:	'	'
Customers	-8,152	-3,708
Brokers, dealers and clearing organizations	-103,450	-17,448
Securities purchased under agreements to resell	-8,990	-49,763
Net financial instruments and other inventory positions owned	38,500	-108,437
Investments	-18,212	-7,381
Other assets	792	-3,511
Payables:	'	'
Customers	7,109	33,332
Brokers, dealers and clearing organizations	83,258	44,114
Securities sold under agreements to repurchase	2,442	0
Accrued compensation	-64,516	-74,265
Other liabilities and accrued expenses	-13,646	-10,211
Decrease in assets held for sale	0	-1,283
Increase/(decrease) in liabilities held for sale	0	-685
Net cash provided by/(used in) operating activities	-44,528	-183,527
Investing Activities:	'	'
Purchases of fixed assets, net	-607	-230
Net cash used in investing activities	-607	-230
Financing Activities:	'	'
Increase/(decrease) in short-term financing	-78,902	-67,996
Increase in securities sold under agreements to repurchase	45,207	132,297
Increase in noncontrolling interests	-2,909	50,562
Repurchase of common stock	-7,346	-13,929
Excess tax benefit from share-based compensation	-47	55
Proceeds from stock option transactions	273	0
Net cash provided by/(used in) financing activities	-43,724	100,989
Currency adjustment:	'	'
Effect of exchange rate changes on cash	11	-88
Net increase in cash and cash equivalents	-88,848	-82,856
Cash and cash equivalents at beginning of year	123,683	105,371
Cash and cash equivalents at end of year	34,835	22,515
Supplemental disclosure of cash flow information –	'	'
Interest	6,019	5,465
Income taxes	19,972	596
Stock Issued During Period, Value, Treasury Stock Reissued	4,156	3,939
Non-cash financing activities –	'	'
Issuance of restricted common stock for annual equity award: 402,074 shares and 431,582 shares for the three months ended March 31, 2014 and 2013, respectively	$16,131	$17,699

Consolidated_Statements_of_Cas1

Consolidated Statements of Cash Flows (Parenthetical)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement of Cash Flows [Abstract]	'	'
Number of common stock issued for retirement plan obligations	103,598	96,049
Number of restricted common stock issued for annual equity award	402,074	431,582

Organization_and_Basis_of_Pres

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Organization and Basis of Presentation	'
	Organization and Basis of Presentation
	Organization
	Piper Jaffray Companies is the parent company of Piper Jaffray & Co. ("Piper Jaffray"), a securities broker dealer and investment banking firm; Piper Jaffray Ltd., a firm providing securities brokerage and mergers and acquisitions services in Europe headquartered in London, England; Advisory Research, Inc. ("ARI"), which provides asset management services to separately managed accounts, closed-end and open-end funds and partnerships; Piper Jaffray Investment Group Inc., which consists of entities providing alternative asset management services; Piper Jaffray Financial Products Inc., Piper Jaffray Financial Products II Inc. and Piper Jaffray Financial Products III Inc., entities that facilitate derivative transactions; and other immaterial subsidiaries. Piper Jaffray Companies and its subsidiaries (collectively, the "Company") operate in two reporting segments: Capital Markets and Asset Management. A summary of the activities of each of the Company’s business segments is as follows:
	Capital Markets
	The Capital Markets segment provides institutional sales, trading and research services and investment banking services. Institutional sales, trading and research services focus on the trading of equity and fixed income products with institutions, government and non-profit entities. Revenues are generated through commissions and sales credits earned on equity and fixed income institutional sales activities, net interest revenues on trading securities held in inventory, and profits and losses from trading these securities. Investment banking services include management of and participation in underwritings, merger and acquisition services and public finance activities. Revenues are generated through the receipt of advisory and financing fees. Also, the Company generates revenue through strategic trading and investing activities, which focus on proprietary investments in municipal bonds, mortgage-backed securities, equity securities, and merchant banking activities involving equity or debt investments in late stage private companies. As certain of these efforts have matured and an investment process has been developed, the Company has created alternative asset management funds in merchant banking and municipal securities in order to invest firm capital as well as to seek capital from outside investors. The Company receives management and performance fees for managing these funds.
	As discussed in Note 5, the Company discontinued its Hong Kong capital markets business in 2012.
	Asset Management
	The Asset Management segment provides traditional asset management services with product offerings in equity securities and master limited partnerships to institutions and individuals. Revenues are generated in the form of management and performance fees. Revenues are also generated through investments in the partnerships and funds that the Company manages.
	As discussed in Note 5, Fiduciary Asset Management, LLC ("FAMCO") was sold in 2013.
	Basis of Presentation
	The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles ("U.S. GAAP") and include the accounts of Piper Jaffray Companies, its wholly owned subsidiaries, and all other entities in which the Company has a controlling financial interest. Noncontrolling interests represent equity interests in consolidated entities that are not attributable, either directly or indirectly, to Piper Jaffray Companies. Noncontrolling interests include the minority equity holders’ proportionate share of the equity in a municipal bond fund, merchant banking fund and private equity investment vehicles. All material intercompany balances have been eliminated.
	The preparation of financial statements and related disclosures in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Although these estimates and assumptions are based on the best information available, actual results could differ from those estimates.
	Reclassifications
	In 2013, the Company reclassified interest revenue and expense associated with its derivative contracts to investment banking or institutional brokerage revenues within the consolidated statements of operations to more accurately reflect the nature and intent of the derivative instrument. The Company reclassified $2.5 million of interest revenue and $2.8 million of interest expense for the three months ended March 31, 2013. This change had no effect on net revenues, net income, shareholders’ equity or cash flows for the period presented.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Summary of Significant Accounting Policies	'
	Summary of Significant Accounting Policies
	Refer to the Company's Annual Report on Form 10-K for the year ended December 31, 2013 for a full description of the Company's significant accounting policies.

Recent_Accounting_Pronouncemen

Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	Adoption of New Accounting Standards
	Investment Companies
	In June 2013, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Updated ("ASU") No. 2013-08, "Financial Services - Investment Companies (Topic 946): Amendments to the Scope, Measurement, and Disclosure Requirements," ("ASU 2013-08") amending FASB Accounting Standards Codification Topic 946, "Financial Services - Investment Companies" ("ASC 946"). The amended guidance changes the approach to the investment company assessment in ASC 946, clarifies the characteristics of an investment company and requires new disclosures for investment company financial statements. ASU 2013-08 was effective for the Company as of January 1, 2014. The adoption of ASU 2013-08 did not impact the Company's results of operations, financial position or disclosures.
	Future Adoption of New Accounting Standards
	Discontinued Operations
	In April 2014, the FASB issued ASU No. 2014-08, "Presentation of Financial Statements (Topic 205) and Property, Plant, and Equipment (Topic 360): Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity," ("ASU 2014-08") amending FASB Accounting Standards Codification Topic 205-20, "Discontinued Operations," ("ASC 205-20"). The amended guidance changes the criteria for reporting discontinued operations and requires new disclosures. ASU 2014-08 is effective for annual and interim periods beginning on or after December 15, 2014, and will be applied prospectively.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2014
Business Combinations [Abstract]	'
Acquisitions	'
	Acquisitions
	On July 12, 2013, the Company completed the purchase of Seattle-Northwest Securities Corporation ("Seattle-Northwest"), a Seattle-based investment bank and broker dealer focused on public finance in the Northwest region of the U.S. The purchase was completed pursuant to the Agreement and Plan of Merger dated April 16, 2013. The acquisition of Seattle-Northwest supports the Company's strategy to grow its public finance business.
	On July 16, 2013, the Company completed the purchase of Edgeview Partners, L.P. ("Edgeview"), a middle-market advisory firm specializing in mergers and acquisitions. The purchase was completed pursuant to the Unit Purchase Agreement dated June 17, 2013. The acquisition of Edgeview further strengthens the Company's mergers and acquisitions position in the middle market and adds resources dedicated to the private equity community.
	The Company paid $32.7 million in cash for Seattle-Northwest and Edgeview, which represented the fair values as of the respective acquisition dates. The Company also entered into acquisition-related compensation arrangements of $14.3 million which consisted of cash, restricted stock and restricted mutual fund shares ("MFRS Awards") of registered funds managed by the Company's asset management business. Compensation expense related to these arrangements will be amortized on a straight-line basis over the requisite service period of two to five years (a weighted average service period of 4.3 years).
	These acquisitions were accounted for pursuant to FASB Accounting Standards Codification Topic 805, "Business Combinations." Accordingly, the purchase price of each acquisition was allocated to the acquired assets and liabilities assumed based on their estimated fair values as of the respective acquisition dates. The excess of the purchase price over the net assets acquired was allocated between goodwill and intangible assets within the Capital Markets segment. The Company recorded $13.8 million of goodwill on the consolidated statements of financial condition, of which $9.1 million is expected to be deductible for income tax purposes. In management's opinion, the goodwill represents the reputation and expertise of Seattle-Northwest and Edgeview in their respective business lines.
	Identifiable intangible assets purchased by the Company consisted of customer relationships and non-competition agreements with acquisition-date fair values estimated to be $6.0 million and $0.7 million, respectively.
	The following table summarizes the estimated fair values of assets acquired and liabilities assumed at the respective dates of acquisition:
	(Dollars in thousands)
	Assets
	Cash and cash equivalents		$	8,014
	Financial instruments and other inventory positions owned		24,074
	Fixed assets		1,247
	Goodwill		13,790
	Intangible assets		6,665
	Other assets		8,922
	Total assets acquired		62,712
	Liabilities
	Payables		1,126
	Financial instruments and other inventory positions sold, but not yet purchased		22,588
	Accrued compensation		1,469
	Other liabilities and accrued expenses		4,789
	Total liabilities assumed		29,972
	Net assets acquired		$	32,740
	Seattle-Northwest and Edgeview results of operations have been included in the Company's consolidated financial statements prospectively from their respective dates of acquisition. These acquisitions have been fully integrated with the Company's existing operations. Accordingly, post-acquisition revenues and net income are not discernible. The following unaudited pro forma financial data assumes the acquisitions had occurred on January 1, 2012, the beginning of the prior annual period in which the acquisitions occurred. Pro forma results have been prepared by adjusting the Company's historical results from continuing operations to include Seattle-Northwest and Edgeview results of operations adjusted for the following changes: depreciation and amortization expenses were adjusted to account for acquisition-date fair value adjustments of fixed assets and intangible assets; compensation and benefits expenses were adjusted to reflect excess partner distributions as compensation expense; and the income tax effect of applying the Company's statutory tax rates to Seattle-Northwest and Edgeview results of operations. The consolidated Company's unaudited pro forma information presented does not necessarily reflect the results of operations that would have resulted had the acquisitions been completed at the beginning of the applicable period presented, does not contemplate anticipated operational efficiencies of the combined entities, nor does it indicate the results of operations in future periods.
		Three Months Ended
		March 31,
	(Dollars in thousands)	2013
	Net revenues	$	113,540
	Net income from continuing operations applicable to Piper Jaffray Companies	$	9,096

Discontinued_Operations

Discontinued Operations	3 Months Ended
	Mar. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]	'
Discontinued Operations	'
	Discontinued Operations
	The Company's Hong Kong capital markets business ceased operations in 2012. In the second quarter of 2013, the Company completed the sale of FAMCO, an asset management subsidiary, for consideration of $4.0 million which consisted of $0.3 million in cash and a $3.7 million note receivable from the buyer. In accordance with the provisions of ASC 205-20, the results from these businesses have been classified as discontinued operations for all periods presented. The Company recorded a $0.5 million net loss from discontinued operations for the three months ended March 31, 2013.
	As part of the FAMCO sale, the Company indemnified the buyer against certain costs and obligations. As of March 31, 2014, a $0.5 million remaining indemnification obligation was included within other liabilities and accrued expenses on the consolidated statements of financial condition. The potential amount of future payments that the Company could be required to make pursuant to the terms of the definitive sale agreement is not limited, however it is not expected to be material.

Financial_Instruments_and_Othe

Financial Instruments and Other Inventory Positions Owned and Financial Instruments and Other Inventory Positions Sold, but Not Yet Purchased	3 Months Ended
	Mar. 31, 2014
Disclosure Financial Instruments And Other Inventory Positions Owned And Financial Instruments And Other Inventory Positions Sold But Not Yet Purchased [Abstract]	'
Financial Instruments and Other Inventory Positions Owned and Financial Instruments and Other Inventory Positions Sold, but Not Yet Purchased	'
	Financial Instruments and Other Inventory Positions Owned and Financial Instruments and Other Inventory Positions Sold, but Not Yet Purchased
	Financial instruments and other inventory positions owned and financial instruments and other inventory positions sold, but not yet purchased were as follows:
		March 31,				December 31,
	(Dollars in thousands)	2014				2013
	Financial instruments and other inventory positions owned:
	Corporate securities:
	Equity securities	$	46,669			$	54,097
	Convertible securities	79,969				80,784
	Fixed income securities	16,120				10,102
	Municipal securities:
	Taxable securities	233,045				232,379
	Tax-exempt securities	438,457				460,865
	Short-term securities	76,261				62,620
	Asset-backed securities	112,079				119,811
	U.S. government agency securities	278,965				304,737
	U.S. government securities	3,090				—
	Derivative contracts	40,733				38,633
	Total financial instruments and other inventory positions owned	1,325,388				1,364,028
	Less noncontrolling interests (1)	(243,892		)		(291,513		)
		$	1,081,496			$	1,072,515
	Financial instruments and other inventory positions sold, but not yet purchased:
	Corporate securities:
	Equity securities	$	85,767			$	69,205
	Fixed income securities	17,029				24,021
	U.S. government agency securities	83,901				120,084
	U.S. government securities	315,666				291,320
	Derivative contracts	10,330				8,203
	Total financial instruments and other inventory positions sold, but not yet purchased	512,693				512,833
	Less noncontrolling interests (2)	(62,420		)		(68,356		)
		$	450,273			$	444,477
	-1	Noncontrolling interests attributable to third party ownership in a consolidated municipal bond fund consist of $103.2 million and $101.8 million of taxable municipal securities, $135.8 million and $183.9 million of tax-exempt municipal securities, and $4.9 million and $5.8 million of derivative contracts as of March 31, 2014 and December 31, 2013, respectively.
	-2	Noncontrolling interests attributable to third party ownership in a consolidated municipal bond fund consist of $61.4 million and $67.4 million of U.S. government securities, and $1.1 million and $1.0 million of derivative contracts as of March 31, 2014 and December 31, 2013, respectively.
	At March 31, 2014 and December 31, 2013, financial instruments and other inventory positions owned in the amount of $908.2 million and $957.5 million, respectively, had been pledged as collateral for short-term financings and repurchase agreements.
	Financial instruments and other inventory positions sold, but not yet purchased represent obligations of the Company to deliver the specified security at the contracted price, thereby creating a liability to purchase the security in the market at prevailing prices. The Company is obligated to acquire the securities sold short at prevailing market prices, which may exceed the amount reflected on the consolidated statements of financial condition. The Company economically hedges changes in the market value of its financial instruments and other inventory positions owned using inventory positions sold, but not yet purchased, interest rate derivatives, credit default swap index contracts, futures and exchange traded options.
	Derivative Contract Financial Instruments
	The Company uses interest rate swaps, interest rate locks, credit default swap index contracts and option contracts to facilitate customer transactions and as a means to manage risk in certain inventory positions. The following describes the Company’s derivatives by the type of transaction or security the instruments are economically hedging.
	Customer matched-book derivatives: The Company enters into interest rate derivative contracts in a principal capacity as a dealer to satisfy the financial needs of its customers.  The Company simultaneously enters into  an interest rate  derivative  contract with a third party for the same notional amount to hedge the interest rate and credit risk of the initial client interest rate derivative contract. In certain limited instances, the Company has only hedged interest rate risk with a third party, and retains uncollateralized credit risk as described below. The instruments use interest rates based upon either the London Interbank Offer Rate (“LIBOR”) index or the Securities Industry and Financial Markets Association (“SIFMA”) index.
	Trading securities derivatives: The Company enters into interest rate derivative contracts to hedge interest rate and market value risks associated with its fixed income securities. The instruments use interest rates based upon either the Municipal Market Data (“MMD”) index, LIBOR or the SIFMA index. The Company also enters into credit default swap index contracts to hedge credit risk associated with its taxable fixed income securities and option contracts to hedge market value risk associated with its convertible securities and asset-backed securities.
	The following table presents the total absolute notional contract amount associated with the Company’s outstanding derivative instruments:
	(Dollars in thousands)				March 31,				December 31,
	Transaction Type or Hedged Security		Derivative Category		2014				2013
	Customer matched-book		Interest rate derivative contract		$	5,287,583			$	5,310,929
	Trading securities		Interest rate derivative contract		255,500				198,500
	Trading securities		Credit default swap index contract		379,215				299,333
	Trading securities		Equity option derivative contract		17,152				17,090
					$	5,939,450			$	5,825,852
	The Company’s derivative contracts do not qualify for hedge accounting, therefore, unrealized gains and losses are recorded on the consolidated statements of operations. The following table presents the Company’s unrealized gains/(losses) on derivative instruments:
					Three Months Ended
	(Dollars in thousands)				March 31,
	Derivative Category		Operations Category		2014				2013
	Interest rate derivative contract		Investment banking		$	(524	)		$	(538	)
	Interest rate derivative contract		Institutional brokerage		532				5,935
	Credit default swap index contract		Institutional brokerage		(1,254		)		(1,874		)
	Equity option derivative contract		Institutional brokerage		948				—
					$	(298	)		$	3,523
	The gross fair market value of all derivative instruments and their location on the Company’s consolidated statements of financial condition prior to counterparty netting are shown below by asset or liability position:
	(Dollars in thousands)				Asset Value at						Liability Value at
					March 31,						March 31,
	Derivative Category		Financial Condition Location		2014				Financial Condition Location		2014
	Interest rate derivative contract		Financial instruments and other inventory positions owned		$	379,037			Financial instruments and other inventory positions sold,  but not yet purchased		$	359,745
	Credit default swap index contract		Financial instruments and other inventory positions owned		8,478				Financial instruments and other inventory positions sold,  but not yet purchased		8,611
	Equity option derivative contract		Financial instruments and other inventory positions owned		74				Financial instruments and other inventory positions sold,  but not yet purchased		1,274
					$	387,589					$	369,630
Derivatives are reported on a net basis by counterparty (i.e., the net payable or receivable for derivative assets and liabilities for a given counterparty) when a legal right of offset exists and on a net basis by cross product when applicable provisions are stated in master netting agreements. Cash collateral received or paid is netted on a counterparty basis, provided a legal right of offset exists.
Credit risk associated with the Company’s derivatives is the risk that a derivative counterparty will not perform in accordance with the terms of the applicable derivative contract. Credit exposure associated with the Company’s derivatives is driven by uncollateralized market movements in the fair value of the contracts with counterparties and is monitored regularly by the Company’s financial risk committee. The Company considers counterparty credit risk in determining derivative contract fair value. The majority of the Company’s  derivative contracts are substantially collateralized by its counterparties, who  are major  financial institutions. The Company has a limited number of counterparties who are not required to post collateral. Based on market movements, the uncollateralized amounts representing the fair value of the derivative contract can become material, exposing the Company to the credit risk of these counterparties. As of March 31, 2014, the Company had $23.0 million of uncollateralized credit exposure with these counterparties (notional contract amount of $200.2 million), including $11.4 million of uncollateralized credit exposure with one counterparty.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'
	Fair Value of Financial Instruments
	Based on the nature of the Company’s business and its role as a “dealer” in the securities industry or as a manager of alternative asset management funds, the fair values of its financial instruments are determined internally. The Company’s processes are designed to ensure that the fair values used for financial reporting are based on observable inputs wherever possible. In the event that observable inputs are not available, unobservable inputs are developed based on an evaluation of all relevant empirical market data, including prices evidenced by market transactions, interest rates, credit spreads, volatilities and correlations and other security-specific information. Valuation adjustments related to illiquidity or counterparty credit risk are also considered. In estimating fair value, the Company may utilize information provided by third-party pricing vendors to corroborate internally-developed fair value estimates.
	The Company employs specific control processes to determine the reasonableness of the fair value of its financial instruments. The Company’s processes are designed to ensure that the internally estimated fair values are accurately recorded and that the data inputs and the valuation techniques used are appropriate, consistently applied, and that the assumptions are reasonable and consistent with the objective of determining fair value. Individuals outside of the trading departments perform independent pricing verification reviews as of each reporting date. The Company has established parameters which set forth when the fair value of securities are independently verified. The selection parameters are generally based upon the type of security, the level of estimation risk of a security, the materiality of the security to the Company’s financial statements, changes in fair value from period to period, and other specific facts and circumstances of the Company’s securities portfolio. In evaluating the initial internally-estimated fair values made by the Company’s traders, the nature and complexity of securities involved (e.g., term, coupon, collateral, and other key drivers of value), level of market activity for securities, and availability of market data are considered. The independent price verification procedures include, but are not limited to, analysis of trade data (both internal and external where available), corroboration to the valuation of positions with similar characteristics, risks and components, or comparison to an alternative pricing source, such as a discounted cash flow model. The Company’s valuation committee, comprised of members of senior management and risk management, provides oversight and overall responsibility for the internal control processes and procedures related to fair value measurements.
	The following is a description of the valuation techniques used to measure fair value.
	Cash Equivalents
	Cash equivalents include highly liquid investments with original maturities of 90 days or less. Actively traded money market funds are measured at their net asset value and classified as Level I.
	Financial Instruments and Other Inventory Positions Owned
	The Company records financial instruments and other inventory positions owned and financial instruments and other inventory positions sold, but not yet purchased at fair value on the consolidated statements of financial condition with unrealized gains and losses reflected on the consolidated statements of operations.
	Equity securities – Exchange traded equity securities are valued based on quoted prices from the exchange for identical assets or liabilities as of the period-end date. To the extent these securities are actively traded and valuation adjustments are not applied, they are categorized as Level I. Non-exchange traded equity securities (principally hybrid preferred securities) are measured primarily using broker quotations, prices observed for recently executed market transactions and internally-developed fair value estimates based on observable inputs and are categorized within Level II of the fair value hierarchy.
	Convertible securities – Convertible securities are valued based on observable trades, when available. Accordingly, these convertible securities are categorized as Level II.
	Corporate fixed income securities – Fixed income securities include corporate bonds which are valued based on recently executed market transactions of comparable size, internally-developed fair value estimates based on observable inputs, or broker quotations. Accordingly, these corporate bonds are categorized as Level II. When observable price quotations or certain observable inputs are not available, fair value is determined using model-based valuation techniques with observable inputs such as specific security contractual terms and yield curves, and unobservable inputs such as credit spreads over U.S. treasury securities. Corporate bonds measured using model-based valuation techniques are categorized as Level III.
	Taxable municipal securities – Taxable municipal securities are valued using recently executed observable trades or market price quotations and therefore are generally categorized as Level II.
	Tax-exempt municipal securities – Tax-exempt municipal securities are valued using recently executed observable trades or market price quotations and therefore are generally categorized as Level II. Certain illiquid tax-exempt municipal securities are valued using market data for comparable securities (maturity and sector) and management judgment to infer an appropriate current yield or other model-based valuation techniques deemed appropriate by management based on the specific nature of the individual security and are therefore categorized as Level III.
	Short-term municipal securities – Short-term municipal securities include auction rate securities, variable rate demand notes, and other short-term municipal securities. Variable rate demand notes and other short-term municipal securities are valued using recently executed observable trades or market price quotations and therefore are generally categorized as Level II. Auction rate securities with limited liquidity are categorized as Level III and are valued using discounted cash flow models with unobservable inputs such as the Company’s expected recovery rate on the securities.
	Asset-backed securities – Asset-backed securities are valued using observable trades, when available. Certain asset-backed securities are valued using models where inputs to the model are directly observable in the market, or can be derived principally from or corroborated by observable market data. These asset-backed securities are categorized as Level II. Other asset-backed securities, which are principally collateralized by residential mortgages, have experienced low volumes of executed transactions resulting in less observable transaction data. Certain asset-backed securities collateralized by residential mortgages are valued using cash flow models that utilize unobservable inputs including credit default rates, prepayment rates, loss severity and valuation yields. As judgment is used to determine the range of these inputs, these asset-backed securities are categorized as Level III.
	U.S. government agency securities – U.S. government agency securities include agency debt bonds and mortgage bonds. Agency debt bonds are valued by using either direct price quotes or price quotes for comparable bond securities and are categorized as Level II. Mortgage bonds include bonds secured by mortgages, mortgage pass-through securities, agency collateralized mortgage-obligation (“CMO”) securities and agency interest-only securities. Mortgage pass-through securities, CMO securities and interest-only securities are valued using recently executed observable trades or other observable inputs, such as prepayment speeds and therefore are generally categorized as Level II. Mortgage bonds are valued using observable market inputs, such as market yields ranging from 79-255 basis points (“bps”) on spreads over U.S. treasury securities, or models based upon prepayment expectations ranging from 149-373 Public Securities Association (“PSA”) prepayment levels. These securities are categorized as Level II.
	U.S. government securities – U.S. government securities include highly liquid U.S. treasury securities which are generally valued using quoted market prices and therefore categorized as Level I. The Company does not transact in securities of countries other than the U.S. government.
	Derivatives – Derivative contracts include interest rate and basis swaps, forward purchase agreements, interest rate locks, futures, options and credit default swap index contracts. These instruments derive their value from underlying assets, reference rates, indices or a combination of these factors. The Company's equity option derivative contracts are valued based on quoted prices from the exchange for identical assets or liabilities as of the period-end date. To the extent these contracts are actively traded and valuation adjustments are not applied, they are categorized as Level I. The Company’s credit default swap index contracts are valued using market price quotations and are classified as Level II. The majority of the Company’s interest rate derivative contracts, including both interest rate swaps and interest rate locks, are valued using market standard pricing models based on the net present value of estimated future cash flows. The valuation models used do not involve material subjectivity as the methodologies do not entail significant judgment and the pricing inputs are market observable, including contractual terms, yield curves and measures of volatility. These instruments are classified as Level II within the fair value hierarchy. Certain interest rate locks transact in less active markets and were valued using valuation models that included the previously mentioned observable inputs and certain unobservable inputs that required significant judgment, such as the premium over the MMD curve. These instruments are classified as Level III.
	Investments
	The Company’s investments valued at fair value include equity investments in private companies, investments in public companies, investments in registered mutual funds, and warrants of public or private companies. Exchange traded direct equity investments in public companies and registered mutual funds are valued based on quoted prices on active markets and classified as Level I. Company-owned warrants, which have a cashless exercise option, are valued based upon the Black-Scholes option-pricing model and certain unobservable inputs. The Company applies a liquidity discount to the value of its warrants in public and private companies. For warrants in private companies, valuation adjustments, based upon management’s judgment, are made to account for differences between the measured security and the stock volatility factors of comparable companies. Company-owned warrants are reported as Level III assets. Equity securities in private companies are valued based on an assessment of each underlying security, considering rounds of financing, third-party transactions and market-based information, including comparable company transactions, trading multiples and changes in market outlook, among other factors. These securities are generally categorized as Level III.
	Fair Value Option – The fair value option permits the irrevocable fair value option election on an instrument-by-instrument basis at initial recognition of an asset or liability or upon an event that gives rise to a new basis of accounting for that instrument. The fair value option was elected for certain merchant banking and other investments at inception to reflect economic events in earnings on a timely basis. Merchant banking and other equity investments of $16.4 million and $16.1 million, included within investments on the consolidated statements of financial condition, are accounted for at fair value and are classified as Level III assets at March 31, 2014 and December 31, 2013, respectively. The realized and unrealized gains from fair value changes included in earnings as a result of electing to apply the fair value option to certain financial assets were $0.3 million and $3.2 million for the three months ended March 31, 2014 and 2013, respectively.
	The following table summarizes quantitative information about the significant unobservable inputs used in the fair value measurement of the Company’s Level III financial instruments as of March 31, 2014:
		Valuation					Weighted
		Technique		Unobservable Input	Range		Average
	Assets:
	Financial instruments and other inventory positions owned:
	Municipal securities:
	Tax-exempt securities	Discounted cash flow		Debt service coverage ratio (2)	5 - 69%		22.20%
	Short-term securities	Discounted cash flow		Expected recovery rate (% of par) (2)	77 - 80%		79.60%
	Asset-backed securities:
	Collateralized by residential mortgages	Discounted cash flow		Credit default rates (3)	2 - 8%		5.20%
				Prepayment rates (4)	2 - 22%		5.10%
				Loss severity (3)	42 - 100%		68.10%
				Valuation yields (3)	5 - 7%		5.90%
	Derivative contracts:
	Interest rate locks	Discounted cash flow		Premium over the MMD curve (1)	53 - 66 bps		63.0 bps
	Investments at fair value:
	Warrants in public and private companies	Black-Scholes option pricing model		Liquidity discount rates (1)	30 - 40%		34.30%
	Warrants in private companies	Black-Scholes option pricing model		Stock volatility factors of comparable companies (2)	26 - 93%		62.60%
	Equity securities in private companies	Market approach		Revenue multiple (2)	2 - 7 times		3.3 times
				EBITDA multiple (2)	9 - 12 times		9.3 times
	Liabilities:
	Financial instruments and other inventory positions sold, but not yet purchased:
	Derivative contracts:
	Interest rate locks	Discounted cash flow		Premium over the MMD curve (1)	5 - 51 bps		19.8 bps
	Sensitivity of the fair value to changes in unobservable inputs:
	-1	Significant increase/(decrease) in the unobservable input in isolation would result in a significantly lower/(higher) fair value measurement.
	-2	Significant increase/(decrease) in the unobservable input in isolation would result in a significantly higher/(lower) fair value measurement.
	-3	Significant changes in any of these inputs in isolation could result in a significantly different fair value. Generally, a change in the assumption used for credit default rates is accompanied by a directionally similar change in the assumption used for the loss severity and a directionally inverse change in the assumption for valuation yields.
	-4	The potential impact of changes in prepayment rates on fair value is dependent on other security-specific factors, such as the par value and structure. Changes in the prepayment rates may result in directionally similar or directionally inverse changes in fair value depending on whether the security trades at a premium or discount to the par value.
	The following table summarizes the valuation of the Company’s financial instruments by pricing observability levels defined in FASB Accounting Standards Codification Topic 820, "Fair Value Measurement" ("ASC 820") as of March 31, 2014:
											Counterparty
											and Cash
											Collateral
	(Dollars in thousands)	Level I			Level II			Level III			Netting (1)			Total
	Assets:
	Financial instruments and other inventory positions owned:
	Corporate securities:
	Equity securities	$	29,873		$	16,796		$	—		$	—		$	46,669
	Convertible securities	—			79,969			—			—			79,969
	Fixed income securities	—			16,020			100			—			16,120
	Municipal securities:
	Taxable securities	—			233,045			—			—			233,045
Tax-exempt securities	—			437,024			1,433			—			438,457
Short-term securities	—			75,605			656			—			76,261
Asset-backed securities	—			4,680			107,399			—			112,079
U.S. government agency securities	—			278,965			—			—			278,965
U.S. government securities	3,090			—			—			—			3,090
Derivative contracts	175			387,350			64			(346,856		)	40,733
Total financial instruments and other inventory positions owned:	33,138			1,529,454			109,652			(346,856		)	1,325,388
Cash equivalents	1,579			—			—			—			1,579
Investments at fair value	27,586			—			60,954			—			88,540
Total assets	$	62,303		$	1,529,454		$	170,606		$	(346,856	)	$	1,415,507
Liabilities:
Financial instruments and other inventory positions sold, but not yet purchased:
Corporate securities:
Equity securities	$	84,568		$	1,199		$	—		$	—		$	85,767
Fixed income securities	—			17,029			—			—			17,029
U.S. government agency securities	—			83,901			—			—			83,901
U.S. government securities	315,666			—			—			—			315,666
Derivative contracts	1,274			362,877			5,479			(359,300		)	10,330
Total financial instruments and other inventory positions sold, but not yet purchased:	$	401,508		$	465,006		$	5,479		$	(359,300	)	$	512,693
-1	Represents cash collateral and the impact of netting on a counterparty basis. The Company had no securities posted as collateral to its counterparties.
The following table summarizes the valuation of the Company’s financial instruments by pricing observability levels defined in ASC 820 as of December 31, 2013:
										Counterparty
										and Cash
										Collateral
(Dollars in thousands)	Level I			Level II			Level III			Netting (1)			Total
Assets:
Financial instruments and other inventory positions owned:
Corporate securities:
Equity securities	$	39,711		$	14,386		$	—		$	—		$	54,097
Convertible securities	—			80,784			—			—			80,784
Fixed income securities	—			10,002			100			—			10,102
Municipal securities:
Taxable securities	—			232,379			—			—			232,379
Tax-exempt securities	—			459,432			1,433			—			460,865
Short-term securities	—			61,964			656			—			62,620
Asset-backed securities	—			12			119,799			—			119,811
U.S. government agency securities	—			304,737			—			—			304,737
Derivative contracts	19			351,589			691			(313,666		)	38,633
Total financial instruments and other inventory positions owned:	39,730			1,515,285			122,679			(313,666		)	1,364,028
Cash equivalents	101,629			—			—			—			101,629
Investments at fair value	20,690			—			49,240			—			69,930
Total assets	$	162,049		$	1,515,285		$	171,919		$	(313,666	)	$	1,535,587
Liabilities:
Financial instruments and other inventory positions sold, but not yet purchased:
Corporate securities:
Equity securities	$	69,205		$	—		$	—		$	—		$	69,205
Fixed income securities	—			24,021			—			—			24,021
U.S. government agency securities	—			120,084			—			—			120,084
U.S. government securities	291,320			—			—			—			291,320
Derivative contracts	1,889			324,065			6,643			(324,394		)	8,203
Total financial instruments and other inventory positions sold, but not yet purchased:	$	362,414		$	468,170		$	6,643		$	(324,394	)	$	512,833
-1	Represents cash collateral and the impact of netting on a counterparty basis. The Company had no securities posted as collateral to its counterparties.
The Company’s Level III assets were $170.6 million and $171.9 million, or 12.1 percent and 11.2 percent of financial instruments measured at fair value at March 31, 2014 and December 31, 2013, respectively. The value of transfers between levels are recognized at the beginning of the reporting period. There were no significant transfers between Level I, Level II or Level III for the three months ended March 31, 2014.
The following tables summarize the changes in fair value associated with Level III financial instruments during the three months ended March 31, 2014 and 2013:
	Balance at														Realized			Unrealized			Balance at
	December 31,									Transfers			Transfers		gains/			gains/			March 31,
(Dollars in thousands)	2013			Purchases			Sales			in			out		(losses) (1)			(losses) (1)			2014
Assets:
Financial instruments and other inventory positions owned:
Corporate securities:
Fixed income securities	$	100		$	—		$	—		$	—		$	—	$	—		$	—		$	100
Municipal securities:
Tax-exempt securities	1,433			—			—			—			—		—			—			1,433
Short-term securities	656			—			—			—			—		—			—			656
Asset-backed securities	119,799			96,725			(114,506		)	—			—		6,270			(889		)	107,399
Derivative contracts	691			2,614			—			—			—		(2,614		)	(627		)	64
Total financial instruments and other inventory positions owned:	122,679			99,339			(114,506		)	—			—		3,656			(1,516		)	109,652
Investments at fair value	49,240			10,000			—			—			—		—			1,714			60,954
Total assets	$	171,919		$	109,339		$	(114,506	)	$	—		$	—	$	3,656		$	198		$	170,606
Liabilities:
Financial instruments and other inventory positions sold, but not yet purchased:
Derivative contracts	$	6,643		$	(16,751	)	$	—		$	—		$	—	$	16,751		$	(1,164	)	$	5,479
Total financial instruments and other inventory positions sold, but not yet purchased:	$	6,643		$	(16,751	)	$	—		$	—		$	—	$	16,751		$	(1,164	)	$	5,479
-1	Realized and unrealized gains/(losses) related to financial instruments, with the exception of customer matched-book derivatives, are reported in institutional brokerage on the consolidated statements of operations. Realized and unrealized gains/(losses) related to customer matched-book derivatives are reported in investment banking. Realized and unrealized gains/(losses) related to investments are reported in investment banking revenues or investment income on the consolidated statements of operations.
	Balance at														Realized			Unrealized			Balance at
	December 31,									Transfers			Transfers		gains/			gains/			March 31,
(Dollars in thousands)	2012			Purchases			Sales			in			out		(losses) (1)			(losses) (1)			2013
Assets:
Financial instruments and other inventory positions owned:
Municipal securities:
Tax-exempt securities	$	1,429		$	1		$	—		$	—		$	—	$	—		$	1		$	1,431
Short-term securities	656			—			—			—			—		—			—			656
Asset-backed securities	116,171			124,450			(142,404		)	—			—		15,272			(5,835		)	107,654
Derivative contracts	827			—			(13		)	—			—		—			1,558			2,372
Total financial instruments and other inventory positions owned:	119,083			124,451			(142,417		)	—			—		15,272			(4,276		)	112,113
Investments at fair value	33,245			5,362			—			—			—		4			3,042			41,653
Total assets	$	152,328		$	129,813		$	(142,417	)	$	—		$	—	$	15,276		$	(1,234	)	$	153,766
Liabilities:
Financial instruments and other inventory positions sold, but not yet purchased:
Corporate securities:
Derivative contracts	$	5,218		$	(5,650	)	$	—		$	—		$	—	$	5,637		$	(4,806	)	$	399
Total financial instruments and other inventory positions sold, but not yet purchased:	$	5,218		$	(5,650	)	$	—		$	—		$	—	$	5,637		$	(4,806	)	$	399
-1	Realized and unrealized gains/(losses) related to financial instruments, with the exception of customer matched-book derivatives, are reported in institutional brokerage on the consolidated statements of operations. Realized and unrealized gains/(losses) related to customer matched-book derivatives are reported in investment banking. Realized and unrealized gains/(losses) related to investments are reported in investment banking revenues or investment income on the consolidated statements of operations.
The carrying values of the Company’s cash, securities either purchased or sold under agreements to resell, receivables and payables either from or to customers and brokers, dealers and clearing organizations and short-term financings approximate fair value due to their liquid or short-term nature.

Variable_Interest_Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2014
Variable Interest Entities Disclosure [Abstract]	'
Variable Interest Entities	'
	Variable Interest Entities
	The Company has investments in and/or acts as the managing partner of various partnerships, limited liability companies, or registered mutual funds. These entities were established for the purpose of investing in securities of public or private companies, or municipal debt obligations and were initially financed through the capital commitments or seed investments of the members.
	Variable Interest Entities ("VIEs") are entities in which equity investors lack the characteristics of a controlling financial interest or do not have sufficient equity at risk for the entity to finance its activities. The determination as to whether an entity is a VIE is based on the amount and nature of the members’ equity investment in the entity. The Company also considers other characteristics such as the power through voting rights or similar rights to direct the activities of an entity that most significantly impact the entity’s economic performance. For those entities that meet the deferral provisions defined by FASB ASU No. 2010-10, "Consolidation: Amendments for Certain Investment Funds," ("ASU 2010-10"), the Company considers characteristics such as the ability to influence the decision making about the entity’s activities and how the entity is financed. The Company has identified certain of the entities described above as VIEs. These VIEs had net assets approximating $0.8 billion at March 31, 2014 and December 31, 2013, respectively. The Company’s exposure to loss from these VIEs is $13.2 million, which is the carrying value of its capital contributions recorded in investments on the consolidated statements of financial condition at March 31, 2014. The Company had no liabilities related to these VIEs at March 31, 2014 and December 31, 2013.
	The Company is required to consolidate all VIEs for which it is considered to be the primary beneficiary. The determination as to whether the Company is considered to be the primary beneficiary is based on whether the Company has both the power to direct the activities of the VIE that most significantly impact the entity’s economic performance and the obligation to absorb losses or the right to receive benefits of the VIE that could potentially be significant to the VIE. For those entities that meet the deferral provisions defined by ASU 2010-10, the determination as to whether the Company is considered to be the primary beneficiary differs in that it is based on whether the Company will absorb a majority of the VIE’s expected losses, receive a majority of the VIE’s expected residual returns, or both. The Company determined it is not the primary beneficiary of these VIEs and accordingly does not consolidate them. Furthermore, the Company has not provided financial or other support to these VIEs that it was not previously contractually required to provide as of March 31, 2014.
	The Company has investments in a grantor trust which was established as part of a nonqualified deferred compensation plan. The Company is the primary beneficiary of the grantor trust. Accordingly, the assets and liabilities of the grantor trust are consolidated by the Company on the consolidated statements of financial condition. See Note 19 for additional information on the nonqualified deferred compensation plan.
	The Company also originates CMOs through secondary market vehicles. The Company's risk of loss with respect to these entities is limited to the fair value of the securities held by the Company.

Receivables_from_and_Payables_

Receivables from and Payables to Brokers, Dealers and Clearing Organizations	3 Months Ended
	Mar. 31, 2014
Brokers and Dealers [Abstract]	'
Receivables from and Payables to Brokers, Dealers and Clearing Organizations	'
	Receivables from and Payables to Brokers, Dealers and Clearing Organizations
	Amounts receivable from brokers, dealers and clearing organizations included:
		March 31,		December 31,
	(Dollars in thousands)	2014		2013
	Receivable arising from unsettled securities transactions	$	107,228	$	59,657
	Deposits paid for securities borrowed	40,888		36,278
	Receivable from clearing organizations	9,862		966
	Deposits with clearing organizations	56,412		20,995
	Securities failed to deliver	2,345		593
	Other	13,828		8,624
		$	230,563	$	127,113
	Amounts payable to brokers, dealers and clearing organizations included:
		March 31,		December 31,
	(Dollars in thousands)	2014		2013
	Payable arising from unsettled securities transactions	$	94,274	$	5,643
	Payable to clearing organizations	788		9,462
	Securities failed to receive	5,789		744
	Other	10,129		11,873
		$	110,980	$	27,722
	Deposits paid for securities borrowed approximate the market value of the securities. Securities failed to deliver and receive represent the contract value of securities that have not been delivered or received by the Company on settlement date.

Collateralized_Securities_Tran

Collateralized Securities Transactions	3 Months Ended
	Mar. 31, 2014
Collateralized Securities Transactions Disclosure [Abstract]	'
Collateralized Securities Transactions	'
	Collateralized Securities Transactions
	The Company’s financing and customer securities activities involve the Company using securities as collateral. In the event that the counterparty does not meet its contractual obligation to return securities used as collateral (e.g., pursuant to the terms of a repurchase agreement), or customers do not deposit additional securities or cash for margin when required, the Company may be exposed to the risk of reacquiring the securities or selling the securities at unfavorable market prices in order to satisfy its obligations to its customers or counterparties. The Company seeks to control this risk by monitoring the market value of securities pledged or used as collateral on a daily basis and requiring adjustments in the event of excess market exposure. The Company also uses unaffiliated third party custodians to administer the underlying collateral for certain of its repurchase agreements and short-term financing to mitigate risk.
	In a reverse repurchase agreement the Company purchases financial instruments from a seller, typically in exchange for cash, and agrees to resell the same or substantially the same financial instruments to the seller at a stated price plus accrued interest in the future. In a repurchase agreement, the Company sells financial instruments to a buyer, typically for cash, and agrees to repurchase the same or substantially the same financial instruments from the buyer at a stated price plus accrued interest at a future date. Even though repurchase and reverse repurchase agreements involve the legal transfer of ownership of financial instruments, they are accounted for as financing arrangements because they require the financial instruments to be repurchased or resold at maturity of the agreement.
	In a securities borrowed transaction, the Company borrows securities from a counterparty in exchange for cash. When the Company returns the securities, the counterparty returns the cash. Interest is generally paid periodically over the life of the transaction.
	In the normal course of business, the Company obtains securities purchased under agreements to resell, securities borrowed and margin agreements on terms that permit it to repledge or resell the securities to others, typically pursuant to repurchase agreements. The Company obtained securities with a fair value of approximately $221.3 million and $212.4 million at March 31, 2014 and December 31, 2013, respectively, of which $212.9 million and $194.9 million, respectively, had been pledged or otherwise transferred to satisfy its commitments under financial instruments and other inventory positions sold, but not yet purchased.
	The following is a summary of the Company’s securities sold under agreements to repurchase ("Repurchase Liabilities"), the fair market value of collateral pledged and the interest rate charged by the Company’s counterparty, which is based on LIBOR plus an applicable margin, as of March 31, 2014:
		Repurchase		Fair Market
	(Dollars in thousands)	Liabilities		Value		Interest Rate
	Term up to 30 day maturities:
	Asset-backed securities	$	6,839	$	9,194	1.65%
	On demand maturities:
	U.S. government securities	45,207		49,064		0.30 - 0.60%
		$	52,046	$	58,258
	Reverse repurchase agreements, repurchase agreements and securities borrowed and loaned are reported on a net basis by counterparty when a legal right of offset exists.
	There were no gross amounts offset on the consolidated statements of financial condition for reverse repurchase agreements, securities borrowed or repurchase agreements at March 31, 2014 and December 31, 2013, respectively, as a legal right of offset did not exist. The Company had no outstanding securities lending arrangements as of March 31, 2014 or December 31, 2013. See Note 6 for information related to the Company's offsetting of derivative contracts.

Investments

Investments	3 Months Ended
	Mar. 31, 2014
Investments [Abstract]	'
Investments	'
	Investments
	The Company’s proprietary investments include investments in private companies and partnerships, registered mutual funds, warrants of public and private companies and private company debt. Investments included:
		March 31,			December 31,
	(Dollars in thousands)	2014			2013
	Investments at fair value	$	88,540		$	69,930
	Investments at cost	19,831			20,709
	Investments accounted for under the equity method	21,884			21,404
	Total investments	130,255			112,043
	Less investments attributable to noncontrolling interests (1)	(27,300		)	(21,137		)
		$	102,955		$	90,906
	-1	Noncontrolling interests are attributable to third party ownership in a consolidated merchant banking fund and private equity investment vehicles.
	Management regularly reviews the Company’s investments in private company debt and has concluded that no valuation allowance is needed as it is probable that all contractual principal and interest will be collected.
	At March 31, 2014, investments carried on a cost basis had an estimated fair market value of $25.5 million. The estimated fair value of these investments was based on an assessment of each underlying security, considering rounds of financing, third-party transactions and market-based information, including comparable company transactions, trading multiples (e.g., multiples of revenue and earnings before interest, taxes, depreciation and amortization ("EBITDA")), among other factors. Because valuation estimates were based upon management’s judgment, investments carried at cost would be categorized as Level III assets in the fair value hierarchy, if they were carried at fair value.
	Investments accounted for under the equity method include general and limited partnership interests. The carrying value of these investments is based on the investment vehicle’s net asset value. The net assets of investment partnerships consist of investments in both marketable and non-marketable securities. The underlying investments held by such partnerships are valued based on the estimated fair value determined by management in our capacity as general partner or investor and, in the case of investments in unaffiliated investment partnerships, are based on financial statements prepared by the unaffiliated general partners.

Other_Assets

Other Assets	3 Months Ended
	Mar. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'
Other Assets	'
	Other Assets
	Other assets included:
		March 31,		December 31,
	(Dollars in thousands)	2014		2013
	Net deferred income tax assets	$	28,110	$	36,252
	Fee receivables	24,738		34,415
	Accrued interest receivables	10,402		9,793
	Forgivable loans, net	10,333		7,879
	Income tax receivables	3,513		—
	Prepaid expenses	4,934		5,237
	Other	9,834		8,516
	Total other assets	$	91,864	$	102,092

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Intangible Assets	'
	Goodwill and Intangible Assets
	The following table presents the changes in the carrying value of goodwill and intangible assets from continuing operations for the three months ended March 31, 2014:
		Capital			Asset
	(Dollars in thousands)	Markets			Management			Total
	Goodwill
	Balance at December 31, 2013	$	13,790		$	196,844		$	210,634
	Goodwill acquired	—			—			—
	Impairment charge	—			—			—
	Balance at March 31, 2014	$	13,790		$	196,844		$	210,634
	Intangible assets
	Balance at December 31, 2013	$	5,316		$	34,614		$	39,930
	Amortization of intangible assets	(743		)	(1,575		)	(2,318		)
	Balance at March 31, 2014	$	4,573		$	33,039		$	37,612

ShortTerm_Financing

Short-Term Financing	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Short-Term Financing	'
	Short-Term Financing
	The following is a summary of short-term financing and the weighted average interest rate on borrowings:
		Outstanding Balance				Weighted Average Interest Rate
		March 31,		December 31,		March 31,		December 31,
	(Dollars in thousands)	2014		2013		2014		2013
	Commercial paper (secured)	$	274,753	$	280,294	1.56	%	1.59	%
	Prime broker arrangement	161,056		234,417		0.82	%	0.9	%
	Total short-term financing	$	435,809	$	514,711
	The Company issues secured commercial paper to fund a portion of its securities inventory. The commercial paper notes (“CP Notes”) can be issued with maturities of 27 days to 270 days from the date of issuance. The CP Notes are issued under three separate programs, CP Series A, CP Series II A and CP Series III A, and are secured by different inventory classes. As of March 31, 2014, the weighted average maturity of CP Series A, CP Series II A and CP Series III A was 151 days, 97 days and 33 days, respectively. The CP Notes are interest bearing or sold at a discount to par with an interest rate based on LIBOR plus an applicable margin.
	The Company has established an arrangement to obtain financing with a prime broker related to its municipal bond funds. Financing under this arrangement is secured by certain securities, primarily municipal securities, and collateral limitations could reduce the amount of funding available under this arrangement. The funding is at the discretion of the prime broker subject to a notice period.
	The Company has committed short-term bank line financing available on a secured basis and uncommitted short-term bank line financing available on both a secured and unsecured basis. The Company uses these credit facilities in the ordinary course of business to fund a portion of its daily operations and the amount borrowed under these credit facilities varies daily based on the Company’s funding needs.
	The Company’s committed short-term bank line financing at March 31, 2014 consisted of a one-year $250 million committed revolving credit facility with U.S. Bank, N.A., which was renewed in December 2013. Advances under this facility are secured by certain marketable securities. The facility includes a covenant that requires the Company’s U.S. broker dealer subsidiary to maintain a minimum net capital of $120 million, and the unpaid principal amount of all advances under this facility will be due on December 27, 2014. The Company pays a nonrefundable commitment fee on the unused portion of the facility on a quarterly basis. At March 31, 2014, the Company had no advances against this line of credit.
	The Company’s uncommitted secured lines at March 31, 2014 totaled $185 million with two banks and are dependent on having appropriate collateral, as determined by the bank agreement, to secure an advance under the line. The availability of the Company’s uncommitted lines are subject to approval by the individual banks each time an advance is requested and may be denied. At March 31, 2014, the Company had no advances against these lines of credit.

Variable_Rate_Senior_Notes

Variable Rate Senior Notes	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Variable Rate Senior Notes	'
	Variable Rate Senior Notes
	On November 30, 2012, the Company entered into a note purchase agreement (“Note Purchase Agreement”) under which the Company issued unsecured variable rate senior notes (“Notes”) in the amount of $125 million. The initial holders of the Notes are certain entities advised by PIMCO. The Notes consist of two classes, Class A Notes and Class B Notes, with principal amounts of $50 million and $75 million, respectively. The Class A Notes bear interest at a rate equal to three-month LIBOR plus 4.00 percent and mature on May 31, 2014. The Class B Notes bear interest at a rate equal to three-month LIBOR plus 4.50 percent and mature on November 30, 2015. Interest on the Notes is adjustable and payable quarterly. The unpaid principal amounts are due in full on the respective maturity dates and may not be prepaid by the Company.
	The Note Purchase Agreement includes customary events of default, including failure to pay principal when due or failure to pay interest within five business days of when due, any representation or warranty in the Note Purchase Agreement proving untrue in any material respect when made by the Company, failure to comply with the covenants in the Note Purchase Agreement, failure to pay or another event of default under other material indebtedness in an amount exceeding $10 million, bankruptcy or insolvency of the Company or any of its subsidiaries or a change in control of the Company. If there is any event of default under the Note Purchase Agreement, the noteholders may declare the entire principal and any accrued interest on the Notes to be due and payable and exercise other customary remedies.
	The Note Purchase Agreement includes covenants that, among other things, require the Company to maintain a minimum consolidated tangible net worth and regulatory net capital, limit the Company's leverage ratio and require the Company to maintain a minimum ratio of operating cash flow to fixed charges. With respect to the net capital covenant, the Company's U.S. broker dealer subsidiary is required to maintain minimum net capital of $120 million. At March 31, 2014, the Company was in compliance with all covenants.
	The Notes are recorded at amortized cost. As of March 31, 2014, the carrying value of the Notes approximates fair value.

Contingencies_and_Commitments

Contingencies and Commitments	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Legal Contingencies	'
	Contingencies and Commitments
	Legal Contingencies
	The Company has been named as a defendant in various legal actions, including complaints and litigation and arbitration claims, arising from its business activities. Such actions include claims related to securities brokerage and investment banking activities, and certain class actions that primarily allege violations of securities laws and seek unspecified damages, which could be substantial. Also, the Company is involved from time to time in investigations and proceedings by governmental agencies and self-regulatory organizations (“SROs”) which could result in adverse judgments, settlement, penalties, fines or other relief.
	The Company has established reserves for potential losses that are probable and reasonably estimable that may result from pending and potential legal actions, investigations and regulatory proceedings. In many cases, however, it is inherently difficult to determine whether any loss is probable or even possible or to estimate the amount or range of any potential loss, particularly where proceedings may be in relatively early stages or where plaintiffs are seeking substantial or indeterminate damages. Matters frequently need to be more developed before a loss or range of loss can reasonably be estimated.
	Given uncertainties regarding the timing, scope, volume and outcome of pending and potential legal actions, investigations and regulatory proceedings and other factors, the amounts of reserves and ranges of reasonably possible losses are difficult to determine and of necessity subject to future revision. Subject to the foregoing, management of the Company believes, based on currently available information, after consultation with outside legal counsel and taking into account its established reserves, that pending legal actions, investigations and regulatory proceedings will be resolved with no material adverse effect on the consolidated statements of financial condition, results of operations or cash flows of the Company. However, if during any period a potential adverse contingency should become probable or resolved for an amount in excess of the established reserves, the results of operations and cash flows in that period and the financial condition as of the end of that period could be materially adversely affected. In addition, there can be no assurance that material losses will not be incurred from claims that have not yet been brought to the Company’s attention or are not yet determined to be reasonably possible.
	Operating Lease Commitments
	The Company leases office space throughout the United States and in a limited number of foreign countries where the Company’s international operations reside. Aggregate minimum lease commitments under operating leases as of March 31, 2014 are as follows:
	(Dollars in thousands)
	Remainder of 2014	$	8,422
	2015	11,186
	2016	11,385
	2017	9,680
	2018	9,380
	Thereafter	34,907
		$	84,960

Shareholders_Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2014
Equity [Abstract]	'
Shareholders' Equity	'
	Shareholders’ Equity
	Share Repurchases
	In the third quarter of 2012, the Company’s board of directors authorized the repurchase of up to $100.0 million in common shares through September 30, 2014. During the three months ended March 31, 2014, the Company did not repurchase any shares of the Company's outstanding common stock related to this authorization. The Company has $39.5 million remaining under this authorization. The Company also purchases shares of common stock from restricted stock award recipients upon the award vesting as recipients sell shares to meet their employment tax obligations. The Company purchased 182,615 shares or $7.3 million of the Company’s common stock for this purpose during the three months ended March 31, 2014.
	Issuance of Shares
	During the three months ended March 31, 2014, the Company issued 103,598 common shares out of treasury stock in fulfillment of $4.2 million in obligations under the Piper Jaffray Companies Retirement Plan (the “Retirement Plan”) and issued 445,114 common shares out of treasury stock as a result of employee restricted share vesting and exercise transactions as discussed in Note 19. During the three months ended March 31, 2013, the Company issued 96,049 common shares out of treasury stock in fulfillment of $3.9 million in obligations under the Retirement Plan and issued 669,221 common shares out of treasury stock as a result of employee restricted share vesting.

Noncontrolling_Interests

Noncontrolling Interests	3 Months Ended
	Mar. 31, 2014
Noncontrolling Interest [Abstract]	'
Noncontrolling Interests	'
	Noncontrolling Interests
	The consolidated financial statements include the accounts of Piper Jaffray Companies, its wholly owned subsidiaries and other entities in which the Company has a controlling financial interest. Noncontrolling interests represent equity interests in consolidated entities that are not attributable, either directly or indirectly, to Piper Jaffray Companies. Noncontrolling interests include the minority equity holders’ proportionate share of the equity in a municipal bond fund of $122.3 million, a merchant banking fund of $19.3 million and private equity investment vehicles aggregating $8.0 million as of March 31, 2014. As of December 31, 2013, noncontrolling interests included the minority equity holders’ proportionate share of the equity in a municipal bond fund of $126.3 million, a merchant banking fund of $14.1 million and private equity investment vehicles aggregating $7.0 million.
	Ownership interests in entities held by parties other than the Company’s common shareholders are presented as noncontrolling interests within shareholders’ equity, separate from the Company’s own equity. Revenues, expenses and net income or loss are reported on the consolidated statements of operations on a consolidated basis, which includes amounts attributable to both the Company’s common shareholders and noncontrolling interests. Net income or loss is then allocated between the Company and noncontrolling interests based upon their relative ownership interests. Net income applicable to noncontrolling interests is deducted from consolidated net income to determine net income applicable to the Company. There was no other comprehensive income or loss attributed to noncontrolling interests for the three months ended March 31, 2014 and 2013, respectively.
		Common						Total
		Shareholders’			Noncontrolling			Shareholders’
	(Dollars in thousands)	Equity			Interests			Equity
	Balance at December 31, 2013	$	734,676		$	147,396		$	882,072
	Net income	17,748			5,138			22,886
	Amortization/issuance of restricted stock	17,776			—			17,776
	Issuance of treasury shares for options exercised	273			—			273
	Repurchase of common stock for employee tax withholding	(7,346		)	—			(7,346		)
	Issuance of treasury shares for 401k match	4,156			—			4,156
	Shares reserved/issued for director compensation	120			—			120
	Other comprehensive income	51			—			51
	Fund capital withdrawals, net	—			(2,909		)	(2,909		)
	Balance at March 31, 2014	$	767,454		$	149,625		$	917,079

Compensation_Plans

Compensation Plans	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Compensation Plans	'
	Compensation Plans
	Stock-Based Compensation Plans
	The Company maintains two stock-based compensation plans, the Piper Jaffray Companies Amended and Restated 2003 Annual and Long-Term Incentive Plan (the “Incentive Plan”) and the 2010 Employment Inducement Award Plan (the “Inducement Plan”). The Company’s equity awards are recognized on the consolidated statements of operations at grant date fair value over the service period of the award, net of estimated forfeitures.
	The following table provides a summary of the Company’s outstanding equity awards (in shares or units) as of March 31, 2014:
	Incentive Plan
	Restricted Stock
	Annual grants	825,343
	Sign-on grants	425,527
		1,250,870
	Inducement Plan
	Restricted Stock	29,159
	Total restricted stock related to compensation	1,280,029
	ARI deal consideration (1)	104,496
	Total restricted stock outstanding	1,384,525
	Incentive Plan
	Restricted Stock Units
	Leadership grants	290,536
	Incentive Plan
	Stock options outstanding	359,072
	-1	The Company issued restricted stock as part of deal consideration in conjunction with the acquisition of ARI.
	Incentive Plan
	The Incentive Plan permits the grant of equity awards, including restricted stock, restricted stock units and non-qualified stock options, to the Company’s employees and directors for up to 7.0 million shares of common stock (1.0 million shares remained available for future issuance under the Incentive Plan as of March 31, 2014). The Company believes that such awards help align the interests of employees and directors with those of shareholders and serve as an employee retention tool. The Incentive Plan provides for accelerated vesting of awards if there is a severance event, a change in control of the Company (as defined in the Incentive Plan), in the event of a participant’s death, and at the discretion of the compensation committee of the Company’s board of directors.
	Restricted Stock Awards
	Restricted stock grants are valued at the market price of the Company’s common stock on the date of grant and are amortized over the related requisite service period. The Company grants shares of restricted stock to current employees as part of year-end compensation (“Annual Grants”) and as a retention tool. Employees may receive restricted stock upon initial hiring or as a retention award (“Sign-on Grants”).
	The Company’s Annual Grants are made each year in February. Annual Grants vest ratably over three years in equal installments. The Annual Grants provide for continued vesting after termination of employment, so long as the employee does not violate certain post-termination restrictions set forth in the award agreement or any agreements entered into upon termination. The Company determined the service inception date precedes the grant date for the Annual Grants, and that the post-termination restrictions do not meet the criteria for an in-substance service condition, as defined by FASB Accounting Standards Codification Topic 718, "Compensation – Stock Compensation" ("ASC 718"). Accordingly, restricted stock granted as part of the Annual Grants is expensed in the one-year period in which those awards are deemed to be earned, which is generally the calendar year preceding the February grant date. For example, the Company recognized compensation expense during fiscal 2013 for its February 2014 Annual Grant. If an equity award related to the Annual Grants is forfeited as a result of violating the post-termination restrictions, the lower of the fair value of the award at grant date or the fair value of the award at the date of forfeiture is recorded within the consolidated statements of operations as a reversal of compensation expense.
	Sign-on Grants are used as a recruiting tool for new employees and are issued to current employees as a retention tool. These awards have both cliff and ratable vesting terms, and the employees must fulfill service requirements in exchange for rights to the awards. Compensation expense is amortized on a straight-line basis from the grant date over the requisite service period, generally two to five years. Employees forfeit unvested shares upon termination of employment and a reversal of compensation expense is recorded.
	Annually, the Company grants stock to its non-employee directors. The stock-based compensation paid to non-employee directors is fully expensed on the grant date and included within outside services expense on the consolidated statements of operations.
	Restricted Stock Units
	The Company granted restricted stock units to its leadership team (“Leadership Grants”) in May 2012 and 2013, respectively. The units will vest and convert to shares of common stock at the end of each 36-month performance period only if the Company satisfies predetermined market conditions over the performance period. Under the terms of the grants, the number of units that will vest and convert to shares will be based on the Company achieving specified market conditions during each performance period as described below. Compensation expense is amortized on a straight-line basis over the three-year requisite service period based on the fair value of the award on the grant date. The market condition must be met for the awards to vest and compensation cost will be recognized regardless if the market condition is satisfied. Employees forfeit unvested share units upon termination of employment with a corresponding reversal of compensation expense.
	Up to 50 percent of the award can be earned based on the Company’s total shareholder return relative to members of a predetermined peer group and up to 50 percent of the award can be earned based on the Company’s total shareholder return. The fair value of the awards on the grant date were determined using a Monte Carlo simulation with the following assumptions:
			Risk-free	Expected Stock
	Grant Year		Interest Rate	Price Volatility
	2013		0.40%	44.00%
	2012		0.38%	47.60%
	Because a portion of the award vesting depends on the Company’s total shareholder return relative to a peer group, the valuation modeled the performance of the peer group as well as the correlation between the Company and the peer group. The expected stock price volatility assumptions were determined using historical volatility as correlation coefficients can only be developed through historical volatility. The risk-free interest rates were determined based on three-year U.S. Treasury bond yields.
	Stock Options
	The Company previously granted options to purchase Piper Jaffray Companies common stock to employees and non-employee directors in fiscal years 2004 through 2008. Employee and director options were expensed by the Company on a straight-line basis over the required service period, based on the estimated fair value of the award on the date of grant using a Black-Scholes option-pricing model. As described above pertaining to the Company’s Annual Grants of restricted shares, stock options granted to employees were expensed in the calendar year preceding the annual February grant date. For example, the Company recognized compensation expense during fiscal 2007 for its February 2008 option grant. The maximum term of the stock options granted to employees and directors is ten years. The Company has not granted stock options since 2008.
	Inducement Plan
	In 2010, the Company established the Inducement Plan in conjunction with the acquisition of ARI. The Company granted $7.0 million in restricted stock (158,801 shares) under the Inducement Plan to ARI employees upon closing of the transaction. These shares vest ratably over five years in equal annual installments ending on March 1, 2015. Inducement Plan awards are amortized as compensation expense on a straight-line basis over the vesting period. Employees forfeit unvested Inducement Plan shares upon termination of employment and a reversal of compensation expense is recorded.
	Stock-Based Compensation Activity
	The Company recorded total compensation expense within continuing operations of $5.3 million and $0.6 million for the three months ended March 31, 2014 and 2013, respectively, related to employee restricted stock and restricted stock unit awards. Total compensation cost includes year-end compensation for Annual Grants and the amortization of Sign-on Grants, less forfeitures of $0.3 million for the three months ended March 31, 2013. There were no forfeitures for the three months ended March 31, 2014. The tax benefit related to stock-based compensation costs totaled $2.0 million and $0.2 million for the three months ended March 31, 2014 and 2013, respectively.
	The following table summarizes the changes in the Company’s unvested restricted stock (including the unvested restricted stock issued as part of the deal consideration for ARI) under the Incentive Plan and Inducement Plan for the three months ended March 31, 2014:
		Unvested		Weighted Average
		Restricted Stock		Grant Date
		(in Shares)		Fair Value
	December 31, 2013	1,582,062		$	35.25
	Granted	402,074		40.12
	Vested	(599,611	)	37.58
	Canceled	—		—
	March 31, 2014	1,384,525		$	35.66
	The following summarizes the changes in the Company’s unvested restricted stock units under the Incentive Plan for the three months ended March 31, 2014:
		Unvested		Weighted Average
		Restricted		Grant Date
		Stock Units		Fair Value
	December 31, 2013	290,536		$	15.83
	Granted	—		—
	Vested	—		—
	Canceled	—		—
	March 31, 2014	290,536		$	15.83
	As of March 31, 2014, there was $11.8 million of total unrecognized compensation cost related to restricted stock and restricted stock units expected to be recognized over a weighted average period of 2.73 years.
	The following table summarizes the changes in the Company’s outstanding stock options for the three months ended March 31, 2014:
						Weighted Average
				Weighted		Remaining
	Options		Average		Contractual Term	Aggregate
	Outstanding		Exercise Price		(in Years)	Intrinsic Value
December 31, 2013	469,289		$	44.83	2	$	288,318
Granted	—		—
Exercised	(8,573	)	31.88
Canceled	(55	)	39.62
Expired	(101,589	)	47.48
March 31, 2014	359,072		$	44.39	2.2	$	1,757,075
Options exercisable at March 31, 2014	359,072		$	44.39	2.2	$	1,757,075
As of March 31, 2014, there was no unrecognized compensation cost related to stock options expected to be recognized over future years.
The intrinsic value and resulting tax benefit realized from option exercises were immaterial for the three months ended March 31, 2014 and 2013, respectively.
Deferred Compensation Plans
In 2013, the Company adopted a nonqualified deferred compensation plan, an unfunded plan which allows certain highly compensated employees, at their election, to defer a percentage of their base salary, commissions and/or cash bonuses. The deferrals vest immediately and are non-forfeitable. The amounts deferred under this plan are held in a grantor trust. The Company invests, as a principal, in investments to economically hedge its obligation under the nonqualified deferred compensation plan. Investments in the grantor trust, consisting of mutual funds, totaled $5.8 million as of March 31, 2014, and are included in investments on the consolidated statements of financial condition. The compensation deferred by the employees is expensed in the period earned. The deferred compensation liability was $5.8 million as of March 31, 2014. Changes in the fair value of the investments made by the Company are reported in investment income/(loss) and changes in the corresponding deferred compensation liability are reflected as compensation and benefits expenses on the consolidated statements of operations.
In 2012, the Company established the Piper Jaffray Companies Mutual Fund Restricted Share Investment Plan, a deferred compensation plan which allows eligible employees to elect to receive a portion of the incentive compensation they would otherwise receive in the form of restricted stock, instead in MFRS Awards of registered funds managed by the Company's asset management business. MFRS Awards are awarded to qualifying employees in February of each year, and represent a portion of their compensation for performance in the preceding year similar to the Company's Annual Grants. MFRS Awards vest ratably over three years in equal installments and provide for continued vesting after termination of employment so long as the employee does not violate certain post-termination restrictions set forth in the award agreement or any agreement entered into upon termination. Forfeitures are recorded as a reduction of compensation and benefits expense within the consolidated statements of operations.
The Company has also granted MFRS Awards to new employees as a recruiting tool. Employees must fulfill service requirements in exchange for rights to the awards. Compensation expense from these awards will be amortized on a straight-line basis over the requisite service period of two to five years.

Earnings_Per_Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Earnings Per Share
	The Company calculates earnings per share using the two-class method. Basic earnings per common share is computed by dividing net income/(loss) applicable to Piper Jaffray Companies’ common shareholders by the weighted average number of common shares outstanding for the period. Net income/(loss) applicable to Piper Jaffray Companies’ common shareholders represents net income/(loss) applicable to Piper Jaffray Companies reduced by the allocation of earnings to participating securities. Losses are not allocated to participating securities. All of the Company’s unvested restricted shares are deemed to be participating securities as they are eligible to share in the profits (e.g., receive dividends) of the Company. The Company’s unvested restricted stock units are not participating securities as they are not eligible to share in the profits of the Company. Diluted earnings per common share is calculated by adjusting the weighted average outstanding shares to assume conversion of all potentially dilutive stock options.
	The computation of earnings per share is as follows:
		Three Months Ended
		March 31,
	(Amounts in thousands, except per share data)	2014			2013
	Net income from continuing operations applicable to Piper Jaffray Companies	$	17,748		$	10,667
	Net loss from discontinued operations	—			(521		)
	Net income applicable to Piper Jaffray Companies	17,748			10,146
	Earnings allocated to participating securities (1)	(1,659		)	(1,180		)
	Net income applicable to Piper Jaffray Companies’ common shareholders (2)	$	16,089		$	8,966
	Shares for basic and diluted calculations:
	Average shares used in basic computation	14,612			15,582
	Stock options	45			28
	Average shares used in diluted computation	14,657			15,610
	Earnings/(loss) per basic common share:
	Income from continuing operations	$	1.1		$	0.6
	Loss from discontinued operations	—			(0.03		)
	Earnings per basic common share	$	1.1		$	0.58
	Earnings/(loss) per diluted common share:
	Income from continuing operations	$	1.1		$	0.6
	Loss from discontinued operations	—			(0.03		)
	Earnings per diluted common share	$	1.1		$	0.57
	-1	Represents the allocation of earnings to participating securities. Losses are not allocated to participating securities. Participating securities include all of the Company’s unvested restricted shares. The weighted average participating shares outstanding were 1,510,839 and 2,055,679 for the three months ended March 31, 2014 and 2013, respectively.
	-2	Net income/(loss) applicable to Piper Jaffray Companies’ common shareholders for diluted and basic EPS may differ under the two-class method as a result of adding the effect of the assumed exercise of stock options to dilutive shares outstanding, which alters the ratio used to allocate earnings to Piper Jaffray Companies’ common shareholders and participating securities for purposes of calculating diluted and basic EPS.
	The anti-dilutive effects from stock options were immaterial for the three months ended March 31, 2014 and 2013.

Segment_Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Segment Reporting	'
	Segment Reporting
	Basis for Presentation
	The Company structures its segments primarily based upon the nature of the financial products and services provided to customers and the Company’s management organization. The Company evaluates performance and allocates resources based on segment pre-tax operating income or loss and segment pre-tax operating margin. Revenues and expenses directly associated with each respective segment are included in determining their operating results. Other revenues and expenses that are not directly attributable to a particular segment are allocated based upon the Company’s allocation methodologies, including each segment’s respective net revenues, use of shared resources, headcount or other relevant measures. The financial management of assets is performed on an enterprise-wide basis. As such, assets are not assigned to the business segments.
	Segment pre-tax operating income and segment pre-tax operating margin exclude the results of discontinued operations.
	Reportable segment financial results from continuing operations are as follows:
		Three Months Ended
		March 31,
	(Dollars in thousands)	2014			2013
	Capital Markets
	Investment banking
	Financing
	Equities	$	35,301		$	14,303
	Debt	13,539			17,032
	Advisory services	39,728			9,556
	Total investment banking	88,568			40,891
	Institutional sales and trading
	Equities	24,260			20,735
	Fixed income	25,238			24,388
	Total institutional sales and trading	49,498			45,123
	Management and performance fees	1,737			1,019
	Investment income	10,378			6,137
	Long-term financing expenses	(1,740		)	(1,949		)
	Net revenues	148,441			91,221
	Operating expenses (1)	120,930			78,458
	Segment pre-tax operating income	$	27,511		$	12,763
	Segment pre-tax operating margin	18.5		%	14		%
		Three Months Ended
		March 31,
	(Dollars in thousands)	2014			2013
	Asset Management
	Management and performance fees
	Management fees	$	19,136		$	17,086
	Performance fees	86			351
	Total management and performance fees	19,222			17,437
	Investment income	470			875
	Net revenues	19,692			18,312
	Operating expenses (1)	14,490			12,907
	Segment pre-tax operating income	$	5,202		$	5,405
	Segment pre-tax operating margin	26.4		%	29.5		%
	Total
	Net revenues	$	168,133		$	109,533
	Operating expenses (1)	135,420			91,365
	Pre-tax operating income	$	32,713		$	18,168
	Pre-tax operating margin	19.5		%	16.6		%
	-1	Operating expenses include intangible asset amortization expense as set forth in the table below:
		Three Months Ended
		March 31,
	(Dollars in thousands)	2014			2013
	Capital Markets	$	743		$	—
	Asset Management	1,575			1,661
	Total intangible asset amortization expense	$	2,318		$	1,661
	Geographic Areas
	The Company operates in both U.S. and non-U.S. markets. The Company’s non-U.S. business activities are principally conducted through European locations. Net revenues and long-lived assets for the Company's Asian location was not significant. Net revenues disclosed in the following table reflect the regional view, with financing revenues allocated to geographic locations based upon the location of the capital market, advisory revenues allocated based upon the location of the investment banking team and net institutional sales and trading revenues allocated based upon the location of the client. Asset management revenues are allocated to the U.S. based upon the geographic location of the Company’s asset management team. Net revenues exclude discontinued operations for all periods presented.
		Three Months Ended
		March 31,
	(Dollars in thousands)	2014			2013
	Net revenues:
	United States	$	165,325		$	105,726
	Europe	2,808			3,807
	Consolidated	$	168,133		$	109,533
	Long-lived assets are allocated to geographic locations based upon the location of the asset. The following table presents long-lived assets by geographic region:
		March 31,			December 31,
	(Dollars in thousands)	2014			2013
Long-lived assets:
United States	$	285,320		$	296,516
Europe	6,346			6,414
Consolidated	$	291,666		$	302,930

Net_Capital_Requirements_and_O

Net Capital Requirements and Other Regulatory Matters	3 Months Ended
	Mar. 31, 2014
Banking and Thrift [Abstract]	'
Net Capital Requirements and Other Regulatory Matters	'
	Net Capital Requirements and Other Regulatory Matters
	Piper Jaffray is registered as a securities broker dealer with the SEC and is a member of various SROs and securities exchanges. The Financial Industry Regulatory Authority (“FINRA”) serves as Piper Jaffray’s primary SRO. Piper Jaffray is subject to the uniform net capital rule of the SEC and the net capital rule of FINRA. Piper Jaffray has elected to use the alternative method permitted by the SEC rule, which requires that it maintain minimum net capital of the greater of $1.0 million or 2 percent of aggregate debit balances arising from customer transactions, as such term is defined in the SEC rule. Under its rules, FINRA may prohibit a member firm from expanding its business or paying dividends if resulting net capital would be less than 5 percent of aggregate debit balances. Advances to affiliates, repayment of subordinated debt, dividend payments and other equity withdrawals by Piper Jaffray are subject to certain notification and other provisions of SEC and FINRA rules. In addition, Piper Jaffray is subject to certain notification requirements related to withdrawals of excess net capital.
	At March 31, 2014, net capital calculated under the SEC rule was $185.2 million, and exceeded the minimum net capital required under the SEC rule by $184.2 million.
	The Company’s short-term committed credit facility of $250 million and its variable rate senior notes include covenants requiring Piper Jaffray to maintain minimum net capital of $120 million.
	Piper Jaffray Ltd., a broker dealer subsidiary registered in the United Kingdom, was subject to the capital requirements of the Prudential Regulation Authority and the Financial Conduct Authority. As of March 31, 2014, Piper Jaffray Ltd. was in compliance with the capital requirements of the Prudential Regulation Authority and the Financial Conduct Authority.

Acquisitions_Tables

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2014
Business Combinations [Abstract]	'
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	'
	The following table summarizes the estimated fair values of assets acquired and liabilities assumed at the respective dates of acquisition:
	(Dollars in thousands)
	Assets
	Cash and cash equivalents		$	8,014
	Financial instruments and other inventory positions owned		24,074
	Fixed assets		1,247
	Goodwill		13,790
	Intangible assets		6,665
	Other assets		8,922
	Total assets acquired		62,712
	Liabilities
	Payables		1,126
	Financial instruments and other inventory positions sold, but not yet purchased		22,588
	Accrued compensation		1,469
	Other liabilities and accrued expenses		4,789
	Total liabilities assumed		29,972
	Net assets acquired		$	32,740
Business Acquisition, Pro Forma Information	'
	The consolidated Company's unaudited pro forma information presented does not necessarily reflect the results of operations that would have resulted had the acquisitions been completed at the beginning of the applicable period presented, does not contemplate anticipated operational efficiencies of the combined entities, nor does it indicate the results of operations in future periods.
		Three Months Ended
		March 31,
	(Dollars in thousands)	2013
	Net revenues	$	113,540
	Net income from continuing operations applicable to Piper Jaffray Companies	$	9,096

Financial_Instruments_and_Othe1

Financial Instruments and Other Inventory Positions Owned and Financial Instruments and Other Inventory Positions Sold, but Not Yet Purchased (Tables)	3 Months Ended
	Mar. 31, 2014
Disclosure Financial Instruments And Other Inventory Positions Owned And Financial Instruments And Other Inventory Positions Sold But Not Yet Purchased [Abstract]	'
Financial Instruments and Other Inventory Positions Owned and Financial Instruments and Other Inventory Positions Sold, but not yet Purchased	'
	Financial instruments and other inventory positions owned and financial instruments and other inventory positions sold, but not yet purchased were as follows:
		March 31,				December 31,
	(Dollars in thousands)	2014				2013
	Financial instruments and other inventory positions owned:
	Corporate securities:
	Equity securities	$	46,669			$	54,097
	Convertible securities	79,969				80,784
	Fixed income securities	16,120				10,102
	Municipal securities:
	Taxable securities	233,045				232,379
	Tax-exempt securities	438,457				460,865
	Short-term securities	76,261				62,620
	Asset-backed securities	112,079				119,811
	U.S. government agency securities	278,965				304,737
	U.S. government securities	3,090				—
	Derivative contracts	40,733				38,633
	Total financial instruments and other inventory positions owned	1,325,388				1,364,028
	Less noncontrolling interests (1)	(243,892		)		(291,513		)
		$	1,081,496			$	1,072,515
	Financial instruments and other inventory positions sold, but not yet purchased:
	Corporate securities:
	Equity securities	$	85,767			$	69,205
	Fixed income securities	17,029				24,021
	U.S. government agency securities	83,901				120,084
	U.S. government securities	315,666				291,320
	Derivative contracts	10,330				8,203
	Total financial instruments and other inventory positions sold, but not yet purchased	512,693				512,833
	Less noncontrolling interests (2)	(62,420		)		(68,356		)
		$	450,273			$	444,477
	-1	Noncontrolling interests attributable to third party ownership in a consolidated municipal bond fund consist of $103.2 million and $101.8 million of taxable municipal securities, $135.8 million and $183.9 million of tax-exempt municipal securities, and $4.9 million and $5.8 million of derivative contracts as of March 31, 2014 and December 31, 2013, respectively.
	-2	Noncontrolling interests attributable to third party ownership in a consolidated municipal bond fund consist of $61.4 million and $67.4 million of U.S. government securities, and $1.1 million and $1.0 million of derivative contracts as of March 31, 2014 and December 31, 2013, respectively.
Total Absolute Notional Contract Amount	'
	The following table presents the total absolute notional contract amount associated with the Company’s outstanding derivative instruments:
	(Dollars in thousands)				March 31,				December 31,
	Transaction Type or Hedged Security		Derivative Category		2014				2013
	Customer matched-book		Interest rate derivative contract		$	5,287,583			$	5,310,929
	Trading securities		Interest rate derivative contract		255,500				198,500
	Trading securities		Credit default swap index contract		379,215				299,333
	Trading securities		Equity option derivative contract		17,152				17,090
					$	5,939,450			$	5,825,852
Unrealized Gains/(Losses) on Derivative Instruments	'
	The following table presents the Company’s unrealized gains/(losses) on derivative instruments:
					Three Months Ended
	(Dollars in thousands)				March 31,
	Derivative Category		Operations Category		2014				2013
	Interest rate derivative contract		Investment banking		$	(524	)		$	(538	)
	Interest rate derivative contract		Institutional brokerage		532				5,935
	Credit default swap index contract		Institutional brokerage		(1,254		)		(1,874		)
	Equity option derivative contract		Institutional brokerage		948				—
					$	(298	)		$	3,523
Gross Fair Market Value of Derivative Instruments and Location on Consolidated Statements of Financial Condition Prior to Counterparty and Cash Collateral Netting by Asset or Liability Position	'
	The gross fair market value of all derivative instruments and their location on the Company’s consolidated statements of financial condition prior to counterparty netting are shown below by asset or liability position:
	(Dollars in thousands)				Asset Value at						Liability Value at
					March 31,						March 31,
	Derivative Category		Financial Condition Location		2014				Financial Condition Location		2014
	Interest rate derivative contract		Financial instruments and other inventory positions owned		$	379,037			Financial instruments and other inventory positions sold,  but not yet purchased		$	359,745
	Credit default swap index contract		Financial instruments and other inventory positions owned		8,478				Financial instruments and other inventory positions sold,  but not yet purchased		8,611
	Equity option derivative contract		Financial instruments and other inventory positions owned		74				Financial instruments and other inventory positions sold,  but not yet purchased		1,274
					$	387,589					$	369,630

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Information about Significant Unobservable Inputs used in Fair Value Measurement	'
	The following table summarizes quantitative information about the significant unobservable inputs used in the fair value measurement of the Company’s Level III financial instruments as of March 31, 2014:
		Valuation					Weighted
		Technique		Unobservable Input	Range		Average
	Assets:
	Financial instruments and other inventory positions owned:
	Municipal securities:
	Tax-exempt securities	Discounted cash flow		Debt service coverage ratio (2)	5 - 69%		22.20%
	Short-term securities	Discounted cash flow		Expected recovery rate (% of par) (2)	77 - 80%		79.60%
	Asset-backed securities:
	Collateralized by residential mortgages	Discounted cash flow		Credit default rates (3)	2 - 8%		5.20%
				Prepayment rates (4)	2 - 22%		5.10%
				Loss severity (3)	42 - 100%		68.10%
				Valuation yields (3)	5 - 7%		5.90%
	Derivative contracts:
	Interest rate locks	Discounted cash flow		Premium over the MMD curve (1)	53 - 66 bps		63.0 bps
	Investments at fair value:
	Warrants in public and private companies	Black-Scholes option pricing model		Liquidity discount rates (1)	30 - 40%		34.30%
	Warrants in private companies	Black-Scholes option pricing model		Stock volatility factors of comparable companies (2)	26 - 93%		62.60%
	Equity securities in private companies	Market approach		Revenue multiple (2)	2 - 7 times		3.3 times
				EBITDA multiple (2)	9 - 12 times		9.3 times
	Liabilities:
	Financial instruments and other inventory positions sold, but not yet purchased:
	Derivative contracts:
	Interest rate locks	Discounted cash flow		Premium over the MMD curve (1)	5 - 51 bps		19.8 bps
	Sensitivity of the fair value to changes in unobservable inputs:
	-1	Significant increase/(decrease) in the unobservable input in isolation would result in a significantly lower/(higher) fair value measurement.
	-2	Significant increase/(decrease) in the unobservable input in isolation would result in a significantly higher/(lower) fair value measurement.
	-3	Significant changes in any of these inputs in isolation could result in a significantly different fair value. Generally, a change in the assumption used for credit default rates is accompanied by a directionally similar change in the assumption used for the loss severity and a directionally inverse change in the assumption for valuation yields.
	-4	The potential impact of changes in prepayment rates on fair value is dependent on other security-specific factors, such as the par value and structure. Changes in the prepayment rates may result in directionally similar or directionally inverse changes in fair value depending on whether the security trades at a premium or discount to the par value.
Valuation of Financial Instruments by Pricing Observability Levels	'
	The following table summarizes the valuation of the Company’s financial instruments by pricing observability levels defined in FASB Accounting Standards Codification Topic 820, "Fair Value Measurement" ("ASC 820") as of March 31, 2014:
											Counterparty
											and Cash
											Collateral
	(Dollars in thousands)	Level I			Level II			Level III			Netting (1)			Total
	Assets:
	Financial instruments and other inventory positions owned:
	Corporate securities:
	Equity securities	$	29,873		$	16,796		$	—		$	—		$	46,669
	Convertible securities	—			79,969			—			—			79,969
	Fixed income securities	—			16,020			100			—			16,120
	Municipal securities:
	Taxable securities	—			233,045			—			—			233,045
	Tax-exempt securities	—			437,024			1,433			—			438,457
	Short-term securities	—			75,605			656			—			76,261
	Asset-backed securities	—			4,680			107,399			—			112,079
	U.S. government agency securities	—			278,965			—			—			278,965
	U.S. government securities	3,090			—			—			—			3,090
	Derivative contracts	175			387,350			64			(346,856		)	40,733
	Total financial instruments and other inventory positions owned:	33,138			1,529,454			109,652			(346,856		)	1,325,388
	Cash equivalents	1,579			—			—			—			1,579
	Investments at fair value	27,586			—			60,954			—			88,540
	Total assets	$	62,303		$	1,529,454		$	170,606		$	(346,856	)	$	1,415,507
	Liabilities:
	Financial instruments and other inventory positions sold, but not yet purchased:
	Corporate securities:
	Equity securities	$	84,568		$	1,199		$	—		$	—		$	85,767
	Fixed income securities	—			17,029			—			—			17,029
	U.S. government agency securities	—			83,901			—			—			83,901
	U.S. government securities	315,666			—			—			—			315,666
	Derivative contracts	1,274			362,877			5,479			(359,300		)	10,330
	Total financial instruments and other inventory positions sold, but not yet purchased:	$	401,508		$	465,006		$	5,479		$	(359,300	)	$	512,693
	-1	Represents cash collateral and the impact of netting on a counterparty basis. The Company had no securities posted as collateral to its counterparties.
	The following table summarizes the valuation of the Company’s financial instruments by pricing observability levels defined in ASC 820 as of December 31, 2013:
											Counterparty
											and Cash
											Collateral
	(Dollars in thousands)	Level I			Level II			Level III			Netting (1)			Total
	Assets:
	Financial instruments and other inventory positions owned:
	Corporate securities:
	Equity securities	$	39,711		$	14,386		$	—		$	—		$	54,097
	Convertible securities	—			80,784			—			—			80,784
	Fixed income securities	—			10,002			100			—			10,102
	Municipal securities:
	Taxable securities	—			232,379			—			—			232,379
	Tax-exempt securities	—			459,432			1,433			—			460,865
	Short-term securities	—			61,964			656			—			62,620
	Asset-backed securities	—			12			119,799			—			119,811
	U.S. government agency securities	—			304,737			—			—			304,737
	Derivative contracts	19			351,589			691			(313,666		)	38,633
	Total financial instruments and other inventory positions owned:	39,730			1,515,285			122,679			(313,666		)	1,364,028
	Cash equivalents	101,629			—			—			—			101,629
	Investments at fair value	20,690			—			49,240			—			69,930
	Total assets	$	162,049		$	1,515,285		$	171,919		$	(313,666	)	$	1,535,587
	Liabilities:
	Financial instruments and other inventory positions sold, but not yet purchased:
	Corporate securities:
	Equity securities	$	69,205		$	—		$	—		$	—		$	69,205
	Fixed income securities	—			24,021			—			—			24,021
	U.S. government agency securities	—			120,084			—			—			120,084
	U.S. government securities	291,320			—			—			—			291,320
	Derivative contracts	1,889			324,065			6,643			(324,394		)	8,203
Total financial instruments and other inventory positions sold, but not yet purchased:	$	362,414		$	468,170		$	6,643		$	(324,394	)	$	512,833
-1	Represents cash collateral and the impact of netting on a counterparty basis. The Company had no securities posted as collateral to its counterparties.
Changes in Fair Value Associated with Level III Financial Instruments	'
	The following tables summarize the changes in fair value associated with Level III financial instruments during the three months ended March 31, 2014 and 2013:
		Balance at														Realized			Unrealized			Balance at
		December 31,									Transfers			Transfers		gains/			gains/			March 31,
	(Dollars in thousands)	2013			Purchases			Sales			in			out		(losses) (1)			(losses) (1)			2014
	Assets:
	Financial instruments and other inventory positions owned:
	Corporate securities:
	Fixed income securities	$	100		$	—		$	—		$	—		$	—	$	—		$	—		$	100
	Municipal securities:
	Tax-exempt securities	1,433			—			—			—			—		—			—			1,433
	Short-term securities	656			—			—			—			—		—			—			656
	Asset-backed securities	119,799			96,725			(114,506		)	—			—		6,270			(889		)	107,399
	Derivative contracts	691			2,614			—			—			—		(2,614		)	(627		)	64
	Total financial instruments and other inventory positions owned:	122,679			99,339			(114,506		)	—			—		3,656			(1,516		)	109,652
	Investments at fair value	49,240			10,000			—			—			—		—			1,714			60,954
	Total assets	$	171,919		$	109,339		$	(114,506	)	$	—		$	—	$	3,656		$	198		$	170,606
	Liabilities:
	Financial instruments and other inventory positions sold, but not yet purchased:
	Derivative contracts	$	6,643		$	(16,751	)	$	—		$	—		$	—	$	16,751		$	(1,164	)	$	5,479
	Total financial instruments and other inventory positions sold, but not yet purchased:	$	6,643		$	(16,751	)	$	—		$	—		$	—	$	16,751		$	(1,164	)	$	5,479
	-1	Realized and unrealized gains/(losses) related to financial instruments, with the exception of customer matched-book derivatives, are reported in institutional brokerage on the consolidated statements of operations. Realized and unrealized gains/(losses) related to customer matched-book derivatives are reported in investment banking. Realized and unrealized gains/(losses) related to investments are reported in investment banking revenues or investment income on the consolidated statements of operations.
		Balance at														Realized			Unrealized			Balance at
		December 31,									Transfers			Transfers		gains/			gains/			March 31,
	(Dollars in thousands)	2012			Purchases			Sales			in			out		(losses) (1)			(losses) (1)			2013
	Assets:
	Financial instruments and other inventory positions owned:
	Municipal securities:
	Tax-exempt securities	$	1,429		$	1		$	—		$	—		$	—	$	—		$	1		$	1,431
	Short-term securities	656			—			—			—			—		—			—			656
	Asset-backed securities	116,171			124,450			(142,404		)	—			—		15,272			(5,835		)	107,654
	Derivative contracts	827			—			(13		)	—			—		—			1,558			2,372
	Total financial instruments and other inventory positions owned:	119,083			124,451			(142,417		)	—			—		15,272			(4,276		)	112,113
	Investments at fair value	33,245			5,362			—			—			—		4			3,042			41,653
	Total assets	$	152,328		$	129,813		$	(142,417	)	$	—		$	—	$	15,276		$	(1,234	)	$	153,766
	Liabilities:
	Financial instruments and other inventory positions sold, but not yet purchased:
	Corporate securities:
	Derivative contracts	$	5,218		$	(5,650	)	$	—		$	—		$	—	$	5,637		$	(4,806	)	$	399
	Total financial instruments and other inventory positions sold, but not yet purchased:	$	5,218		$	(5,650	)	$	—		$	—		$	—	$	5,637		$	(4,806	)	$	399
	-1	Realized and unrealized gains/(losses) related to financial instruments, with the exception of customer matched-book derivatives, are reported in institutional brokerage on the consolidated statements of operations. Realized and unrealized gains/(losses) related to customer matched-book derivatives are reported in investment banking. Realized and unrealized gains/(losses) related to investments are reported in investment banking revenues or investment income on the consolidated statements of operations.

Receivables_from_and_Payables_1

Receivables from and Payables to Brokers, Dealers and Clearing Organizations (Tables)	3 Months Ended
	Mar. 31, 2014
Brokers and Dealers [Abstract]	'
Brokers, Dealers and Clearing Organizations	'
	Amounts receivable from brokers, dealers and clearing organizations included:
		March 31,		December 31,
	(Dollars in thousands)	2014		2013
	Receivable arising from unsettled securities transactions	$	107,228	$	59,657
	Deposits paid for securities borrowed	40,888		36,278
	Receivable from clearing organizations	9,862		966
	Deposits with clearing organizations	56,412		20,995
	Securities failed to deliver	2,345		593
	Other	13,828		8,624
		$	230,563	$	127,113
	Amounts payable to brokers, dealers and clearing organizations included:
		March 31,		December 31,
	(Dollars in thousands)	2014		2013
	Payable arising from unsettled securities transactions	$	94,274	$	5,643
	Payable to clearing organizations	788		9,462
	Securities failed to receive	5,789		744
	Other	10,129		11,873
		$	110,980	$	27,722

Collateralized_Securities_Tran1

Collateralized Securities Transactions (Tables)	3 Months Ended
	Mar. 31, 2014
Collateralized Securities Transactions Disclosure [Abstract]	'
Summary of Repurchase Liabilities, Fair Market Value of Related Collateral Pledged and Interest Rate Charged	'
	The following is a summary of the Company’s securities sold under agreements to repurchase ("Repurchase Liabilities"), the fair market value of collateral pledged and the interest rate charged by the Company’s counterparty, which is based on LIBOR plus an applicable margin, as of March 31, 2014:
		Repurchase		Fair Market
	(Dollars in thousands)	Liabilities		Value		Interest Rate
	Term up to 30 day maturities:
	Asset-backed securities	$	6,839	$	9,194	1.65%
	On demand maturities:
	U.S. government securities	45,207		49,064		0.30 - 0.60%
		$	52,046	$	58,258

Investments_Tables

Investments (Tables)	3 Months Ended
	Mar. 31, 2014
Investments [Abstract]	'
Schedule of Investments	'
	The Company’s proprietary investments include investments in private companies and partnerships, registered mutual funds, warrants of public and private companies and private company debt. Investments included:
		March 31,			December 31,
	(Dollars in thousands)	2014			2013
	Investments at fair value	$	88,540		$	69,930
	Investments at cost	19,831			20,709
	Investments accounted for under the equity method	21,884			21,404
	Total investments	130,255			112,043
	Less investments attributable to noncontrolling interests (1)	(27,300		)	(21,137		)
		$	102,955		$	90,906
	-1	Noncontrolling interests are attributable to third party ownership in a consolidated merchant banking fund and private equity investment vehicles.

Other_Assets_Tables

Other Assets (Tables)	3 Months Ended
	Mar. 31, 2014
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'
Other Assets	'
	Other assets included:
		March 31,		December 31,
	(Dollars in thousands)	2014		2013
	Net deferred income tax assets	$	28,110	$	36,252
	Fee receivables	24,738		34,415
	Accrued interest receivables	10,402		9,793
	Forgivable loans, net	10,333		7,879
	Income tax receivables	3,513		—
	Prepaid expenses	4,934		5,237
	Other	9,834		8,516
	Total other assets	$	91,864	$	102,092

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Changes in Carrying Value of Goodwill and Intangible Assets	'
	The following table presents the changes in the carrying value of goodwill and intangible assets from continuing operations for the three months ended March 31, 2014:
		Capital			Asset
	(Dollars in thousands)	Markets			Management			Total
	Goodwill
	Balance at December 31, 2013	$	13,790		$	196,844		$	210,634
	Goodwill acquired	—			—			—
	Impairment charge	—			—			—
	Balance at March 31, 2014	$	13,790		$	196,844		$	210,634
	Intangible assets
	Balance at December 31, 2013	$	5,316		$	34,614		$	39,930
	Amortization of intangible assets	(743		)	(1,575		)	(2,318		)
	Balance at March 31, 2014	$	4,573		$	33,039		$	37,612

ShortTerm_Financing_Tables

Short-Term Financing (Tables)	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Summary of Short-Term Financing and Weighted Average Interest Rate on Borrowings	'
	The following is a summary of short-term financing and the weighted average interest rate on borrowings:
		Outstanding Balance				Weighted Average Interest Rate
		March 31,		December 31,		March 31,		December 31,
	(Dollars in thousands)	2014		2013		2014		2013
	Commercial paper (secured)	$	274,753	$	280,294	1.56	%	1.59	%
	Prime broker arrangement	161,056		234,417		0.82	%	0.9	%
	Total short-term financing	$	435,809	$	514,711

Contingencies_and_Commitments_

Contingencies and Commitments (Tables)	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	'
	The Company leases office space throughout the United States and in a limited number of foreign countries where the Company’s international operations reside. Aggregate minimum lease commitments under operating leases as of March 31, 2014 are as follows:
	(Dollars in thousands)
	Remainder of 2014	$	8,422
	2015	11,186
	2016	11,385
	2017	9,680
	2018	9,380
	Thereafter	34,907
		$	84,960

Noncontrolling_Interests_Table

Noncontrolling Interests (Tables)	3 Months Ended
	Mar. 31, 2014
Noncontrolling Interest [Abstract]	'
Changes in Common Shareholders' Equity Attributable to Parent Company and Equity Attributable to Noncontrolling Interests	'
		Common						Total
		Shareholders’			Noncontrolling			Shareholders’
	(Dollars in thousands)	Equity			Interests			Equity
	Balance at December 31, 2013	$	734,676		$	147,396		$	882,072
	Net income	17,748			5,138			22,886
	Amortization/issuance of restricted stock	17,776			—			17,776
	Issuance of treasury shares for options exercised	273			—			273
	Repurchase of common stock for employee tax withholding	(7,346		)	—			(7,346		)
	Issuance of treasury shares for 401k match	4,156			—			4,156
	Shares reserved/issued for director compensation	120			—			120
	Other comprehensive income	51			—			51
	Fund capital withdrawals, net	—			(2,909		)	(2,909		)
	Balance at March 31, 2014	$	767,454		$	149,625		$	917,079

Compensation_Plans_Tables

Compensation Plans (Tables)	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Summary of Outstanding Equity Awards	'
	The following table provides a summary of the Company’s outstanding equity awards (in shares or units) as of March 31, 2014:
	Incentive Plan
	Restricted Stock
	Annual grants	825,343
	Sign-on grants	425,527
		1,250,870
	Inducement Plan
	Restricted Stock	29,159
	Total restricted stock related to compensation	1,280,029
	ARI deal consideration (1)	104,496
	Total restricted stock outstanding	1,384,525
	Incentive Plan
	Restricted Stock Units
	Leadership grants	290,536
	Incentive Plan
	Stock options outstanding	359,072
	-1	The Company issued restricted stock as part of deal consideration in conjunction with the acquisition of ARI.
Schedule of Valuation Assumptions	'
	The fair value of the awards on the grant date were determined using a Monte Carlo simulation with the following assumptions:
			Risk-free	Expected Stock
	Grant Year		Interest Rate	Price Volatility
	2013		0.40%	44.00%
	2012		0.38%	47.60%
Changes in Unvested Restricted Stock	'
	The following table summarizes the changes in the Company’s unvested restricted stock (including the unvested restricted stock issued as part of the deal consideration for ARI) under the Incentive Plan and Inducement Plan for the three months ended March 31, 2014:
		Unvested		Weighted Average
		Restricted Stock		Grant Date
		(in Shares)		Fair Value
	December 31, 2013	1,582,062		$	35.25
	Granted	402,074		40.12
	Vested	(599,611	)	37.58
	Canceled	—		—
	March 31, 2014	1,384,525		$	35.66
Changes in Unvested Restricted Stock Units	'
	The following summarizes the changes in the Company’s unvested restricted stock units under the Incentive Plan for the three months ended March 31, 2014:
		Unvested		Weighted Average
		Restricted		Grant Date
		Stock Units		Fair Value
	December 31, 2013	290,536		$	15.83
	Granted	—		—
	Vested	—		—
	Canceled	—		—
	March 31, 2014	290,536		$	15.83
Changes in Outstanding Stock Options	'
	The following table summarizes the changes in the Company’s outstanding stock options for the three months ended March 31, 2014:
						Weighted Average
				Weighted		Remaining
		Options		Average		Contractual Term	Aggregate
		Outstanding		Exercise Price		(in Years)	Intrinsic Value
	December 31, 2013	469,289		$	44.83	2	$	288,318
	Granted	—		—
	Exercised	(8,573	)	31.88
	Canceled	(55	)	39.62
	Expired	(101,589	)	47.48
	March 31, 2014	359,072		$	44.39	2.2	$	1,757,075
	Options exercisable at March 31, 2014	359,072		$	44.39	2.2	$	1,757,075

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Computation of Earnings per Share	'
	The computation of earnings per share is as follows:
		Three Months Ended
		March 31,
	(Amounts in thousands, except per share data)	2014			2013
	Net income from continuing operations applicable to Piper Jaffray Companies	$	17,748		$	10,667
	Net loss from discontinued operations	—			(521		)
	Net income applicable to Piper Jaffray Companies	17,748			10,146
	Earnings allocated to participating securities (1)	(1,659		)	(1,180		)
	Net income applicable to Piper Jaffray Companies’ common shareholders (2)	$	16,089		$	8,966
	Shares for basic and diluted calculations:
	Average shares used in basic computation	14,612			15,582
	Stock options	45			28
	Average shares used in diluted computation	14,657			15,610
	Earnings/(loss) per basic common share:
	Income from continuing operations	$	1.1		$	0.6
	Loss from discontinued operations	—			(0.03		)
	Earnings per basic common share	$	1.1		$	0.58
	Earnings/(loss) per diluted common share:
	Income from continuing operations	$	1.1		$	0.6
	Loss from discontinued operations	—			(0.03		)
	Earnings per diluted common share	$	1.1		$	0.57
	-1	Represents the allocation of earnings to participating securities. Losses are not allocated to participating securities. Participating securities include all of the Company’s unvested restricted shares. The weighted average participating shares outstanding were 1,510,839 and 2,055,679 for the three months ended March 31, 2014 and 2013, respectively.
	-2	Net income/(loss) applicable to Piper Jaffray Companies’ common shareholders for diluted and basic EPS may differ under the two-class method as a result of adding the effect of the assumed exercise of stock options to dilutive shares outstanding, which alters the ratio used to allocate earnings to Piper Jaffray Companies’ common shareholders and participating securities for purposes of calculating diluted and basic EPS.

Segment_Reporting_Tables

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Reportable Segment Financial Results	'
	Reportable segment financial results from continuing operations are as follows:
		Three Months Ended
		March 31,
	(Dollars in thousands)	2014			2013
	Capital Markets
	Investment banking
	Financing
	Equities	$	35,301		$	14,303
	Debt	13,539			17,032
	Advisory services	39,728			9,556
	Total investment banking	88,568			40,891
	Institutional sales and trading
	Equities	24,260			20,735
	Fixed income	25,238			24,388
	Total institutional sales and trading	49,498			45,123
	Management and performance fees	1,737			1,019
	Investment income	10,378			6,137
	Long-term financing expenses	(1,740		)	(1,949		)
	Net revenues	148,441			91,221
	Operating expenses (1)	120,930			78,458
	Segment pre-tax operating income	$	27,511		$	12,763
	Segment pre-tax operating margin	18.5		%	14		%
		Three Months Ended
		March 31,
	(Dollars in thousands)	2014			2013
	Asset Management
	Management and performance fees
	Management fees	$	19,136		$	17,086
	Performance fees	86			351
	Total management and performance fees	19,222			17,437
	Investment income	470			875
	Net revenues	19,692			18,312
	Operating expenses (1)	14,490			12,907
	Segment pre-tax operating income	$	5,202		$	5,405
	Segment pre-tax operating margin	26.4		%	29.5		%
	Total
	Net revenues	$	168,133		$	109,533
	Operating expenses (1)	135,420			91,365
	Pre-tax operating income	$	32,713		$	18,168
	Pre-tax operating margin	19.5		%	16.6		%
	-1	Operating expenses include intangible asset amortization expense as set forth in the table below:
		Three Months Ended
		March 31,
	(Dollars in thousands)	2014			2013
	Capital Markets	$	743		$	—
	Asset Management	1,575			1,661
	Total intangible asset amortization expense	$	2,318		$	1,661
Schedule of Intangible Asset Amortization Expense	'
	Operating expenses include intangible asset amortization expense as set forth in the table below:
		Three Months Ended
		March 31,
	(Dollars in thousands)	2014			2013
	Capital Markets	$	743		$	—
	Asset Management	1,575			1,661
	Total intangible asset amortization expense	$	2,318		$	1,661
Net Revenues by Geographic Locations	'
	Net revenues exclude discontinued operations for all periods presented.
		Three Months Ended
		March 31,
	(Dollars in thousands)	2014			2013
	Net revenues:
	United States	$	165,325		$	105,726
	Europe	2,808			3,807
	Consolidated	$	168,133		$	109,533
Long-Lived Assets by Geographic Region	'
	Long-lived assets are allocated to geographic locations based upon the location of the asset. The following table presents long-lived assets by geographic region:
		March 31,			December 31,
	(Dollars in thousands)	2014			2013
	Long-lived assets:
	United States	$	285,320		$	296,516
	Europe	6,346			6,414
	Consolidated	$	291,666		$	302,930

Organization_and_Basis_of_Pres1

Organization and Basis of Presentation - Additional Information (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2013
	segment	Interest Revenue [Member]	Interest Expense [Member]
Organization, Consolidation and Presentation of Financial Statements [Line Items]	'	'	'
Number of reportable segments	2	'	'
Reclassified amount	'	$2.50	$2.80

Acquisitions_Additional_Inform

Acquisitions - Additional Information(Details) (USD $)	0 Months Ended	3 Months Ended
	Jul. 16, 2013	Mar. 31, 2014
Business Acquisition [Line Items]	'	'
Goodwill acquired	'	'
Capital Markets	'	'
Business Acquisition [Line Items]	'	'
Goodwill acquired	13,800,000	0
Capital Markets | Customer Relationships	'	'
Business Acquisition [Line Items]	'	'
Intangible assets	6,000,000	'
Capital Markets | Noncompete Agreements	'	'
Business Acquisition [Line Items]	'	'
Intangible assets	700,000	'
Seattle-Northwest Securities Corporation and Edgeview Partners, L.P.	'	'
Business Acquisition [Line Items]	'	'
Consideration transferred	32,700,000	'
Acquisition related compensation arrangements	14,300,000	'
Goodwill amount expected to be deducted for income tax purposes	9,100,000	'
Intangible assets	$6,665,000	'
Seattle-Northwest Securities Corporation and Edgeview Partners, L.P. | Minimum	'	'
Business Acquisition [Line Items]	'	'
Acquisition related compensation arrangement award vesting period	'2 years	'
Seattle-Northwest Securities Corporation and Edgeview Partners, L.P. | Maximum	'	'
Business Acquisition [Line Items]	'	'
Acquisition related compensation arrangement award vesting period	'5 years	'
Seattle-Northwest Securities Corporation and Edgeview Partners, L.P. | Weighted Average	'	'
Business Acquisition [Line Items]	'	'
Acquisition related compensation arrangement award vesting period	'4 years 3 months	'

Acquisitions_Estimated_Fair_Va

Acquisitions - Estimated Fair Values of Assets Acquired and Liabilities Assumed (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Jul. 16, 2013
In Thousands, unless otherwise specified			Seattle-Northwest Securities Corporation and Edgeview Partners, L.P.
Assets	'	'	'
Cash and cash equivalents	'	'	$8,014
Financial instruments and other inventory positions owned	'	'	24,074
Fixed assets	'	'	1,247
Goodwill	210,634	210,634	13,790
Intangible assets	'	'	6,665
Other assets	'	'	8,922
Total assets acquired	'	'	62,712
Liabilities	'	'	'
Payables	'	'	1,126
Financial instruments and other inventory positions sold, but not yet purchased	'	'	22,588
Accrued compensation	'	'	1,469
Other liabilities and accrued expenses	'	'	4,789
Total liabilities assumed	'	'	29,972
Net assets acquired	'	'	$32,740

Acquisitions_Unaudited_Pro_For

Acquisitions - Unaudited Pro Forma Information (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2013
Business Combinations [Abstract]	'
Net revenues	$113,540
Net income from continuing operations applicable to Piper Jaffray Companies	$9,096

Discontinued_Operations_Detail

Discontinued Operations (Details Textual) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Jun. 30, 2013	Mar. 31, 2014
			FAMCO	FAMCO
				Other Liabilities and Accrued Expenses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'
Sale of FAMCO, sale price	'	'	$4,000,000	'
Sale of FAMCO, cash proceeds	'	'	300,000	'
Sale of FAMCO, note receivable received	'	'	3,700,000	'
Loss from discontinued operations, net of tax	0	-521,000	'	'
Sale of FAMCO, indemnification accrual	'	'	'	$500,000

Financial_Instruments_and_Othe2

Financial Instruments and Other Inventory Positions Owned and Financial Instruments and Other Inventory Positions Sold, but Not Yet Purchased (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'	'
Total financial instruments and other inventory positions owned	$1,325,388	$1,364,028
Financial instruments and other inventory positions owned, attributable to noncontrolling interest	-243,892	-291,513
Financial instruments and other inventory positions owned, attributable to parent	1,081,496	1,072,515
Financial instruments and other inventory positions sold, but not yet purchased	512,693	512,833
Financial instruments and other inventory positions owned and pledged as collateral, attributable to noncontrolling interest	-62,420	-68,356
Financial instruments and other inventory positions owned and pledged as collateral, attributable to parent	450,273	444,477
Financial instruments and other inventory positions owned and pledged as collateral	908,217	957,515
Equity securities	'	'
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'	'
Total financial instruments and other inventory positions owned	46,669	54,097
Financial instruments and other inventory positions sold, but not yet purchased	85,767	69,205
Convertible securities	'	'
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'	'
Total financial instruments and other inventory positions owned	79,969	80,784
Fixed income securities	'	'
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'	'
Total financial instruments and other inventory positions owned	16,120	10,102
Financial instruments and other inventory positions sold, but not yet purchased	17,029	24,021
Taxable securities	'	'
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'	'
Total financial instruments and other inventory positions owned	233,045	232,379
Financial instruments and other inventory positions owned, attributable to noncontrolling interest	-103,200	-101,800
Tax-exempt securities	'	'
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'	'
Total financial instruments and other inventory positions owned	438,457	460,865
Financial instruments and other inventory positions owned, attributable to noncontrolling interest	-135,800	-183,900
Short-term securities	'	'
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'	'
Total financial instruments and other inventory positions owned	76,261	62,620
Asset-backed securities	'	'
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'	'
Total financial instruments and other inventory positions owned	112,079	119,811
U.S. government agency securities	'	'
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'	'
Total financial instruments and other inventory positions owned	278,965	304,737
Financial instruments and other inventory positions sold, but not yet purchased	83,901	120,084
U.S. government securities	'	'
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'	'
Total financial instruments and other inventory positions owned	3,090	0
Financial instruments and other inventory positions sold, but not yet purchased	315,666	291,320
Financial instruments and other inventory positions owned and pledged as collateral, attributable to noncontrolling interest	-61,400	-67,400
Derivative contracts	'	'
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'	'
Total financial instruments and other inventory positions owned	40,733	38,633
Financial instruments and other inventory positions owned, attributable to noncontrolling interest	-4,900	-5,800
Financial instruments and other inventory positions sold, but not yet purchased	10,330	8,203
Financial instruments and other inventory positions owned and pledged as collateral, attributable to noncontrolling interest	($1,100)	($1,000)

Financial_Instruments_and_Othe3

Financial Instruments and Other Inventory Positions Owned and Financial Instruments and Other Inventory Positions Sold, but Not Yet Purchased - Total Absolute Notional Contract Amount (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivative [Line Items]	'	'
Absolute Notional Contract Amount of Derivative Instruments	$5,939,450	$5,825,852
Customer matched-book | Interest rate derivative contract	'	'
Derivative [Line Items]	'	'
Absolute Notional Contract Amount of Derivative Instruments	5,287,583	5,310,929
Trading securities | Interest rate derivative contract	'	'
Derivative [Line Items]	'	'
Absolute Notional Contract Amount of Derivative Instruments	255,500	198,500
Trading securities | Credit default swap index contract	'	'
Derivative [Line Items]	'	'
Absolute Notional Contract Amount of Derivative Instruments	379,215	299,333
Trading securities | Equity Option Derivative Contract [Member]	'	'
Derivative [Line Items]	'	'
Absolute Notional Contract Amount of Derivative Instruments	$17,152	$17,090

Financial_Instruments_and_Othe4

Financial Instruments and Other Inventory Positions Owned and Financial Instruments and Other Inventory Positions Sold, but Not Yet Purchased - Unrealized Gains/(Losses) on Derivative Instruments (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Derivative [Line Items]	'	'
Unrealized Gain (Loss) on Derivatives Instruments	($298)	$3,523
Interest rate derivative contract | Investment banking	'	'
Derivative [Line Items]	'	'
Unrealized Gain (Loss) on Derivatives Instruments	-524	-538
Interest rate derivative contract | Institutional brokerage	'	'
Derivative [Line Items]	'	'
Unrealized Gain (Loss) on Derivatives Instruments	532	5,935
Credit default swap index contract | Institutional brokerage	'	'
Derivative [Line Items]	'	'
Unrealized Gain (Loss) on Derivatives Instruments	-1,254	-1,874
Equity Option Derivative Contract [Member] | Institutional brokerage	'	'
Derivative [Line Items]	'	'
Unrealized Gain (Loss) on Derivatives Instruments	$948	$0

Financial_Instruments_and_Othe5

Financial Instruments and Other Inventory Positions Owned and Financial Instruments and Other Inventory Positions Sold, but Not Yet Purchased - Gross Fair Market Value of Derivative Instruments (Details) (USD $)	Mar. 31, 2014
In Thousands, unless otherwise specified
Derivative [Line Items]	'
Fair value of derivative assets, gross	$387,589
Fair value of derivative liabilities, gross	369,630
Financial instruments and other inventory positions owned | Interest rate derivative contract	'
Derivative [Line Items]	'
Fair value of derivative assets, gross	379,037
Financial instruments and other inventory positions owned | Credit default swap index contract	'
Derivative [Line Items]	'
Fair value of derivative assets, gross	8,478
Financial instruments and other inventory positions owned | Equity Option Derivative Contract [Member]	'
Derivative [Line Items]	'
Fair value of derivative assets, gross	74
Financial instruments and other inventory positions sold, but not yet purchased | Interest rate derivative contract	'
Derivative [Line Items]	'
Fair value of derivative liabilities, gross	359,745
Financial instruments and other inventory positions sold, but not yet purchased | Credit default swap index contract	'
Derivative [Line Items]	'
Fair value of derivative liabilities, gross	8,611
Financial instruments and other inventory positions sold, but not yet purchased | Equity Option Derivative Contract [Member]	'
Derivative [Line Items]	'
Fair value of derivative liabilities, gross	$1,274

Financial_Instruments_and_Othe6

Financial Instruments and Other Inventory Positions Owned and Financial Instruments and Other Inventory Positions Sold, but Not Yet Purchased - Additional Information (Details) (USD $)	Mar. 31, 2014
In Millions, unless otherwise specified
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'
Uncollateralized credit exposure	$23
Notional contract amount of derivatives with counterparties not required to post collateral	200.2
Counterparty	'
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]	'
Uncollateralized credit exposure	$11.40

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'
Investments at fair value	$88,540,000	'	$69,930,000
Gains from fair value changes	300,000	3,200,000	'
Transfers of financial assets from Level III	'	'	'
Goodwill impairment	'	'	'
Level III	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'
Investments at fair value	60,954,000	'	49,240,000
Total assets	170,606,000	'	171,919,000
Percentage of Level III assets to financial instruments measured at fair value	12.10%	'	11.20%
Merchant Banking Investments	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'
Investments at fair value	$16,400,000	'	$16,100,000
U.S. government agency securities | Minimum	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'
Market yields basis points spreads to treasury securities (as a percent)	0.79%	'	'
Prepayment expectations based upon PSA prepayment levels	149	'	'
U.S. government agency securities | Maximum	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'
Market yields basis points spreads to treasury securities (as a percent)	2.55%	'	'
Prepayment expectations based upon PSA prepayment levels	373	'	'

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments - Information about Significant Unobservable Inputs used in Fair Value Measurement (Details)	3 Months Ended
	Mar. 31, 2014
Minimum	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	9
Maximum	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	12
Weighted Average	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	9.3
Financial instruments and other inventory positions sold, but not yet purchased | Minimum | Discounted cash flow | Level III | Interest rate derivative contract	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Unamortized premium over the MMD curve	0.05%
Financial instruments and other inventory positions sold, but not yet purchased | Maximum | Discounted cash flow | Level III | Interest rate derivative contract	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Unamortized premium over the MMD curve	0.51%
Financial instruments and other inventory positions sold, but not yet purchased | Weighted Average | Discounted cash flow | Level III | Interest rate derivative contract	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Unamortized premium over the MMD curve	0.20%
Financial instruments and other inventory positions owned | Minimum | Discounted cash flow | Level III | Tax-exempt securities	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Debt service coverage ratio	5.00%
Financial instruments and other inventory positions owned | Minimum | Discounted cash flow | Level III | Short-term securities	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Expected recovery rate (% of par)	77.00%
Financial instruments and other inventory positions owned | Minimum | Discounted cash flow | Level III | Collateralized by Residential mortgages	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Credit default rate	2.00%
Prepayment rates	2.00%
Loss severity	42.00%
Valuation yields	5.00%
Financial instruments and other inventory positions owned | Minimum | Discounted cash flow | Level III | Interest rate derivative contract	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Unamortized premium over the MMD curve	0.53%
Financial instruments and other inventory positions owned | Minimum | Discounted cash flow | Level III | Equity investment in private company	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Revenue multiple	2
Financial instruments and other inventory positions owned | Minimum | Black-Scholes option pricing model | Level III | Warrants in public and private companies	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Liquidity discount rates	30.00%
Financial instruments and other inventory positions owned | Minimum | Black-Scholes option pricing model | Level III | Warrants in private companies	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Stock volatility factors of comparable companies	26.00%
Financial instruments and other inventory positions owned | Maximum | Discounted cash flow | Level III | Tax-exempt securities	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Debt service coverage ratio	69.00%
Financial instruments and other inventory positions owned | Maximum | Discounted cash flow | Level III | Short-term securities	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Expected recovery rate (% of par)	80.00%
Financial instruments and other inventory positions owned | Maximum | Discounted cash flow | Level III | Collateralized by Residential mortgages	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Credit default rate	8.00%
Prepayment rates	22.00%
Loss severity	100.00%
Valuation yields	7.00%
Financial instruments and other inventory positions owned | Maximum | Discounted cash flow | Level III | Interest rate derivative contract	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Unamortized premium over the MMD curve	0.66%
Financial instruments and other inventory positions owned | Maximum | Discounted cash flow | Level III | Equity investment in private company	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Revenue multiple	7
Financial instruments and other inventory positions owned | Maximum | Black-Scholes option pricing model | Level III | Warrants in public and private companies	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Liquidity discount rates	40.00%
Financial instruments and other inventory positions owned | Maximum | Black-Scholes option pricing model | Level III | Warrants in private companies	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Stock volatility factors of comparable companies	93.00%
Financial instruments and other inventory positions owned | Weighted Average | Discounted cash flow | Level III | Tax-exempt securities	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Debt service coverage ratio	22.20%
Financial instruments and other inventory positions owned | Weighted Average | Discounted cash flow | Level III | Short-term securities	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Expected recovery rate (% of par)	79.60%
Financial instruments and other inventory positions owned | Weighted Average | Discounted cash flow | Level III | Collateralized by Residential mortgages	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Credit default rate	5.20%
Prepayment rates	5.10%
Loss severity	68.10%
Valuation yields	5.90%
Financial instruments and other inventory positions owned | Weighted Average | Discounted cash flow | Level III | Interest rate derivative contract	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Unamortized premium over the MMD curve	0.63%
Financial instruments and other inventory positions owned | Weighted Average | Discounted cash flow | Level III | Equity investment in private company	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Revenue multiple	3.3
Financial instruments and other inventory positions owned | Weighted Average | Black-Scholes option pricing model | Level III | Warrants in public and private companies	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Liquidity discount rates	34.30%
Financial instruments and other inventory positions owned | Weighted Average | Black-Scholes option pricing model | Level III | Warrants in private companies	'
Fair Value Inputs Assets and Liabilities Quantitative Information [Line Items]	'
Stock volatility factors of comparable companies	62.60%

Fair_Value_of_Financial_Instru4

Fair Value of Financial Instruments - Valuation of Financial Instruments by Pricing Observability Levels (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	$1,325,388	$1,364,028	'	'
Investments at fair value	88,540	69,930	'	'
Financial instruments and other inventory positions sold, but not yet purchased	512,693	512,833	'	'
Equity securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	46,669	54,097	'	'
Financial instruments and other inventory positions sold, but not yet purchased	85,767	69,205	'	'
Convertible securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	79,969	80,784	'	'
Fixed income securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	16,120	10,102	'	'
Financial instruments and other inventory positions sold, but not yet purchased	17,029	24,021	'	'
Taxable securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	233,045	232,379	'	'
Tax-exempt securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	438,457	460,865	'	'
Short-term securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	76,261	62,620	'	'
Asset-backed securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	112,079	119,811	'	'
U.S. government agency securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	278,965	304,737	'	'
Financial instruments and other inventory positions sold, but not yet purchased	83,901	120,084	'	'
U.S. government securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	3,090	0	'	'
Financial instruments and other inventory positions sold, but not yet purchased	315,666	291,320	'	'
Derivative contracts	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	40,733	38,633	'	'
Financial instruments and other inventory positions sold, but not yet purchased	10,330	8,203	'	'
Level I	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	33,138	39,730	'	'
Cash equivalents	1,579	101,629	'	'
Investments at fair value	27,586	20,690	'	'
Total assets	62,303	162,049	'	'
Financial instruments and other inventory positions sold, but not yet purchased	401,508	362,414	'	'
Level I | Equity securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	29,873	39,711	'	'
Financial instruments and other inventory positions sold, but not yet purchased	84,568	69,205	'	'
Level I | Convertible securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Level I | Fixed income securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Level I | Taxable securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Level I | Tax-exempt securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Level I | Short-term securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Level I | Asset-backed securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Level I | U.S. government agency securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Level I | U.S. government securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	3,090	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	315,666	291,320	'	'
Level I | Derivative contracts	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	175	19	'	'
Financial instruments and other inventory positions sold, but not yet purchased	1,274	1,889	'	'
Level II	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	1,529,454	1,515,285	'	'
Cash equivalents	'	'	'	'
Investments at fair value	'	'	'	'
Total assets	1,529,454	1,515,285	'	'
Financial instruments and other inventory positions sold, but not yet purchased	465,006	468,170	'	'
Level II | Equity securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	16,796	14,386	'	'
Financial instruments and other inventory positions sold, but not yet purchased	1,199	'	'	'
Level II | Convertible securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	79,969	80,784	'	'
Level II | Fixed income securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	16,020	10,002	'	'
Financial instruments and other inventory positions sold, but not yet purchased	17,029	24,021	'	'
Level II | Taxable securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	233,045	232,379	'	'
Level II | Tax-exempt securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	437,024	459,432	'	'
Level II | Short-term securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	75,605	61,964	'	'
Level II | Asset-backed securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	4,680	12	'	'
Level II | U.S. government agency securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	278,965	304,737	'	'
Financial instruments and other inventory positions sold, but not yet purchased	83,901	120,084	'	'
Level II | U.S. government securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Level II | Derivative contracts	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	387,350	351,589	'	'
Financial instruments and other inventory positions sold, but not yet purchased	362,877	324,065	'	'
Level III	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	109,652	122,679	'	'
Cash equivalents	'	'	'	'
Investments at fair value	60,954	49,240	'	'
Total assets	170,606	171,919	'	'
Financial instruments and other inventory positions sold, but not yet purchased	5,479	6,643	'	'
Level III | Equity securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Level III | Convertible securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Level III | Fixed income securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	100	100	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Level III | Taxable securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Level III | Tax-exempt securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	1,433	1,433	'	'
Level III | Short-term securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	656	656	'	'
Level III | Asset-backed securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	107,399	119,799	'	'
Level III | U.S. government agency securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Level III | U.S. government securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Level III | Derivative contracts	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	64	691	'	'
Financial instruments and other inventory positions sold, but not yet purchased	5,479	6,643	'	'
Counterparty and Cash Collateral Netting	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	-346,856	-313,666	'	'
Cash equivalents	'	'	'	'
Investments at fair value	'	'	'	'
Total assets	-346,856	-313,666	'	'
Financial instruments and other inventory positions sold, but not yet purchased	-359,300	-324,394	'	'
Counterparty and Cash Collateral Netting | Equity securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Counterparty and Cash Collateral Netting | Convertible securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Counterparty and Cash Collateral Netting | Fixed income securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Counterparty and Cash Collateral Netting | Taxable securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Counterparty and Cash Collateral Netting | Tax-exempt securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Counterparty and Cash Collateral Netting | Short-term securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Counterparty and Cash Collateral Netting | Asset-backed securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Counterparty and Cash Collateral Netting | U.S. government agency securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Counterparty and Cash Collateral Netting | U.S. government securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	'	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Counterparty and Cash Collateral Netting | Derivative contracts	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	-346,856	-313,666	'	'
Financial instruments and other inventory positions sold, but not yet purchased	-359,300	-324,394	'	'
Total	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	1,325,388	1,364,028	'	'
Cash equivalents	1,579	101,629	'	'
Investments at fair value	88,540	69,930	'	'
Total assets	1,415,507	1,535,587	'	'
Financial instruments and other inventory positions sold, but not yet purchased	512,693	512,833	'	'
Total | Equity securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	46,669	54,097	'	'
Financial instruments and other inventory positions sold, but not yet purchased	85,767	69,205	'	'
Total | Convertible securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	79,969	80,784	'	'
Total | Fixed income securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	16,120	10,102	'	'
Financial instruments and other inventory positions sold, but not yet purchased	17,029	24,021	'	'
Total | Taxable securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	233,045	232,379	'	'
Total | Tax-exempt securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	438,457	460,865	'	'
Total | Short-term securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	76,261	62,620	'	'
Total | Asset-backed securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	112,079	119,811	'	'
Total | U.S. government agency securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	278,965	304,737	'	'
Financial instruments and other inventory positions sold, but not yet purchased	83,901	120,084	'	'
Total | U.S. government securities	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	3,090	'	'	'
Financial instruments and other inventory positions sold, but not yet purchased	315,666	291,320	'	'
Total | Derivative contracts	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Financial instruments and other inventory positions owned	40,733	38,633	'	'
Financial instruments and other inventory positions sold, but not yet purchased	10,330	8,203	'	'
Financial instruments and other inventory positions sold, but not yet purchased	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	5,479	6,643	399	5,218
Financial instruments and other inventory positions sold, but not yet purchased | Derivative contracts	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	$5,479	$6,643	$399	$5,218

Fair_Value_of_Financial_Instru5

Fair Value of Financial Instruments - Changes in Fair Value Associated with Level III Financial Instruments (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Beginning balance	$171,919	$152,328
Purchases	109,339	129,813
Sales	-114,506	-142,417
Transfers in	'	'
Transfers out	'	'
Realized gains/ (losses)	3,656	15,276
Unrealized gains/ (losses)	198	-1,234
Ending balance	170,606	153,766
Financial instruments and other inventory positions sold, but not yet purchased	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Beginning balance	6,643	5,218
Purchases	-16,751	-5,650
Sales	'	'
Transfers in	'	'
Transfers out	'	'
Realized gains/(losses)	16,751	5,637
Unrealized gains/ (losses)	-1,164	-4,806
Ending balance	5,479	399
Financial instruments and other inventory positions sold, but not yet purchased | Derivative contracts	'	'
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Beginning balance	6,643	5,218
Purchases	-16,751	-5,650
Sales	'	'
Transfers in	'	'
Transfers out	'	'
Realized gains/(losses)	16,751	5,637
Unrealized gains/ (losses)	-1,164	-4,806
Ending balance	5,479	399
Financial instruments and other inventory positions owned	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Beginning balance	122,679	119,083
Purchases	99,339	124,451
Sales	-114,506	-142,417
Transfers in	'	'
Transfers out	'	'
Realized gains/ (losses)	3,656	15,272
Unrealized gains/ (losses)	-1,516	-4,276
Ending balance	109,652	112,113
Financial instruments and other inventory positions owned | Fixed income securities	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Beginning balance	100	'
Purchases	0	'
Sales	0	'
Transfers in	0	'
Transfers out	0	'
Realized gains/ (losses)	0	'
Unrealized gains/ (losses)	0	'
Ending balance	100	'
Financial instruments and other inventory positions owned | Tax-exempt securities	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Beginning balance	1,433	1,429
Purchases	'	1
Sales	'	'
Transfers in	'	'
Transfers out	'	'
Realized gains/ (losses)	'	'
Unrealized gains/ (losses)	'	1
Ending balance	1,433	1,431
Financial instruments and other inventory positions owned | Short-term securities	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Beginning balance	656	656
Purchases	'	'
Sales	'	'
Transfers in	'	'
Transfers out	'	'
Realized gains/ (losses)	'	'
Unrealized gains/ (losses)	'	'
Ending balance	656	656
Financial instruments and other inventory positions owned | Asset-backed securities	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Beginning balance	119,799	116,171
Purchases	96,725	124,450
Sales	-114,506	-142,404
Transfers in	'	'
Transfers out	'	'
Realized gains/ (losses)	6,270	15,272
Unrealized gains/ (losses)	-889	-5,835
Ending balance	107,399	107,654
Financial instruments and other inventory positions owned | Derivative contracts	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Beginning balance	691	827
Purchases	2,614	'
Sales	'	-13
Transfers in	'	'
Transfers out	'	'
Realized gains/ (losses)	-2,614	'
Unrealized gains/ (losses)	-627	1,558
Ending balance	64	2,372
Investments [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'
Beginning balance	49,240	33,245
Purchases	10,000	5,362
Sales	'	'
Transfers in	'	'
Transfers out	'	'
Realized gains/ (losses)	'	4
Unrealized gains/ (losses)	1,714	3,042
Ending balance	$60,954	$41,653

Variable_Interest_Entities_Add

Variable Interest Entities - Additional Information (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Variable Interest Entities Disclosure [Abstract]	'	'
Variable interest entity, nonconsolidated total assets	$800,000,000	$800,000,000
Variable interest entities, exposure to loss	13,200,000	'
VIE liabilities	$0	'

Receivables_from_and_Payables_2

Receivables from and Payables to Brokers, Dealers and Clearing Organizations - Amounts Receivable from Brokers, Dealers and Clearing Organizations (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Disclosure Amounts Receivable From Brokers Dealers And Clearing Organizations [Abstract]	'	'
Receivable arising from unsettled securities transactions	$107,228	$59,657
Deposits paid for securities borrowed	40,888	36,278
Receivable from clearing organizations	9,862	966
Deposits with clearing organizations	56,412	20,995
Securities failed to deliver	2,345	593
Other	13,828	8,624
Brokers, dealers and clearing organizations	$230,563	$127,113

Receivables_from_and_Payables_3

Receivables from and Payables to Brokers, Dealers and Clearing Organizations - Amounts Payable to Brokers, Dealers and Clearing Organizations (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Disclosure Amounts Payable To Brokers Dealers And Clearing Organizations [Abstract]	'	'
Payable arising from unsettled securities transactions	$94,274	$5,643
Payable to clearing organizations	788	9,462
Securities failed to receive	5,789	744
Other	10,129	11,873
Brokers, dealers and clearing organizations	$110,980	$27,722

Collateralized_Securities_Tran2

Collateralized Securities Transactions - Summary of Repurchase Liabilities, Fair Market Value of Related Collateral Pledged and Interest Rate Charged (Details) (USD $)	Mar. 31, 2014
In Thousands, unless otherwise specified
Assets Sold under Agreements to Repurchase [Line Items]	'
Repurchase Liabilities	$52,046
Fair Market Value	58,258
Maturity up to 30 days [Member] | Asset-backed securities	'
Assets Sold under Agreements to Repurchase [Line Items]	'
Repurchase Liabilities	6,839
Fair Market Value	9,194
Interest Rate	1.65%
On demand maturities | US Treasury and Government [Member]	'
Assets Sold under Agreements to Repurchase [Line Items]	'
Repurchase Liabilities	45,207
Fair Market Value	$49,064
On demand maturities | US Treasury and Government [Member] | Minimum	'
Assets Sold under Agreements to Repurchase [Line Items]	'
Interest Rate	0.30%
On demand maturities | US Treasury and Government [Member] | Maximum	'
Assets Sold under Agreements to Repurchase [Line Items]	'
Interest Rate	0.60%

Collateralized_Securities_Tran3

Collateralized Securities Transactions - Additional Information (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Collateralized Securities Transactions Disclosure [Abstract]	'	'
Reverse Repurchase, Offset Value	$0	$0
Securities purchased under agreements to resell, securities borrowed and margin agreements on terms that permit to repledge or resell the securities to others	221,300,000	212,400,000
Securities either pledged or otherwise transferred to others in connection with financing activities or to satisfy commitments under financial instruments and other inventory positions sold, but not yet purchased	212,900,000	194,900,000
Securities loaned	$0	$0

Investments_Details

Investments (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investments [Abstract]	'	'
Investments at fair value	$88,540	$69,930
Investments at cost	19,831	20,709
Investments accounted for under the equity method	21,884	21,404
Total investments	130,255	112,043
Less investments attributable to noncontrolling interests	-27,300	-21,137
Investments less portion attributable to noncontolling interest	$102,955	$90,906

Investments_Additional_Informa

Investments - Additional Information (Details) (USD $)	Mar. 31, 2014
Investment [Line Items]	'
Estimated fair market value of investments carried at cost	$25,500,000
Investments [Member]	'
Investment [Line Items]	'
Valuation allowances and reserves, balance	$0

Other_Assets_Details

Other Assets (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]	'	'
Net deferred income tax assets	$28,110	$36,252
Fee receivables	24,738	34,415
Accrued interest receivables	10,402	9,793
Forgivable loans, net	10,333	7,879
Income tax receivables	3,513	0
Prepaid expenses	4,934	5,237
Other	9,834	8,516
Total other assets	$91,864	$102,092

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets - Changes in Carrying Value of Goodwill and Intangible Assets (Details) (USD $)	0 Months Ended	3 Months Ended
In Thousands, unless otherwise specified	Jul. 16, 2013	Mar. 31, 2014	Mar. 31, 2013
Goodwill	'	'	'
Goodwill beginning balance	'	$210,634	'
Goodwill acquired	'	'	'
Impairment charge	'	'	'
Goodwill ending balance	'	210,634	'
Intangible assets	'	'	'
Intangible assets beginning balance	'	39,930	'
Amortization of intangible assets	'	-2,318	-1,661
Intangible assets ending balance	'	37,612	'
Capital Markets	'	'	'
Goodwill	'	'	'
Goodwill beginning balance	'	13,790	'
Goodwill acquired	-13,800	0	'
Impairment charge	'	0	'
Goodwill ending balance	'	13,790	'
Intangible assets	'	'	'
Intangible assets beginning balance	'	5,316	'
Amortization of intangible assets	'	-743	0
Intangible assets ending balance	'	4,573	'
Asset Mgmt [Member]	'	'	'
Goodwill	'	'	'
Goodwill beginning balance	'	196,844	'
Goodwill acquired	'	'	'
Impairment charge	'	'	'
Goodwill ending balance	'	196,844	'
Intangible assets	'	'	'
Intangible assets beginning balance	'	34,614	'
Amortization of intangible assets	'	-1,575	-1,661
Intangible assets ending balance	'	$33,039	'

ShortTerm_Financing_Summary_of

Short-Term Financing - Summary of Short Term Financing and Weighted Average Interest Rate on Borrowings (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Short-term Debt [Line Items]	'	'
Oustanding Balance	$435,809,000	$514,711,000
Commercial paper (secured)	'	'
Short-term Debt [Line Items]	'	'
Oustanding Balance	274,753,000	280,294,000
Weighted Average Interest Rate	1.56%	1.59%
Prime broker arrangement	'	'
Short-term Debt [Line Items]	'	'
Oustanding Balance	$161,056,000	$234,417,000
Weighted Average Interest Rate	0.82%	0.90%

ShortTerm_Financing_Additional

Short-Term Financing - Additional Information (Detail) (USD $)

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Commercial paper (secured)

Commercial paper (secured)

Commercial paper (secured)

Commercial paper (secured)

Commercial paper (secured)

Commercial paper (secured)

Commercial paper (secured)

Line of Credit [Member]

Line of Credit [Member]

Committed Credit Facility [Member]

Committed Credit Facility [Member]

program

Minimum

Maximum

CP Series A

CP Series II A

CP Series III A

Committed Credit Facility [Member]

Uncommitted Credit Facility [Member]

Covenant Requirement

banks

Short-term Debt [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Senior secured commercial paper notes, maturity period

'

'

'

'

'27 days

'270 days

'

'

'

'

'

'

'

Number of commercial paper programs

'

'

3

'

'

'

'

'

'

'

'

'

'

Weighted average maturity period

'

'

'

'

'

'

'151 days

'97 days

'33 days

'

'

'

'

Debt term

'

'

'

'

'

'

'

'

'

'1 year

'

'

'

Line of credity, maximum borrowing capacity

'

'

'

'

'

'

'

'

'

$250,000,000

$185,000,000

$250,000,000

'

Minimum net capital required

'

'

'

'

'

'

'

'

'

'

'

'

120,000,000

Short-term financing

$435,809,000

$514,711,000

$274,753,000

$280,294,000

'

'

'

'

'

$0

$0

'

'

Number of banks

'

'

'

'

'

'

'

'

'

'

2

'

'

Variable_Rate_Senior_Notes_Add

Variable Rate Senior Notes - Additional Information (Details) (USD $)	3 Months Ended			3 Months Ended		3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Nov. 30, 2012	Nov. 30, 2012	Mar. 31, 2014	Nov. 30, 2012	Mar. 31, 2014	Mar. 31, 2014
		Senior Notes	Senior Notes	Senior Notes	Senior Notes	Senior Notes	Senior Notes
		class	Class A Variable Rate Senior Notes Due May 2014	Class A Variable Rate Senior Notes Due May 2014	Class B Variable Rate Senior Notes Due November 2015	Class B Variable Rate Senior Notes Due November 2015	Covenant Requirement
				Three-Month LIBOR		Three-Month LIBOR
Debt Instrument [Line Items]	'	'	'	'	'	'	'
Face amount	'	$125	$50	'	$75	'	'
Number of classes of notes	'	2	'	'	'	'	'
Basis spread on variable rate	'	'	'	4.00%	'	4.50%	'
Note purchase agreement, days to pay interest	'5 days	'	'	'	'	'	'
Note purchase agreement, event of default, maximum indebtedness	10	'	'	'	'	'	'
Minimum net capital required	'	'	'	'	'	'	$120

Contingencies_and_Commitments_1

Contingencies and Commitments - Aggregate Minimum Lease Commitments under Operating Leases (Details) (USD $)	Mar. 31, 2014
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]	'
Remainder of 2014	$8,422
2015	11,186
2016	11,385
2017	9,680
2018	9,380
Thereafter	34,907
Total	$84,960

Shareholders_Equity_Additional

Shareholders' Equity - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Sep. 30, 2012
Stockholders Equity Note [Line Items]	'	'	'
Repurchase of common stock, authorized amount	'	'	$100,000,000
Common stock repurchase authorized, remaining amount	39,500,000	'	'
Shares of common stock purchased from restricted stock award related to recipients' employment tax obligations	182,615	'	'
Repurchase of common stock for employee tax withholding	7,346,000	'	'
Number of common stock issued for retirement plan obligations	103,598	96,049	'
Stock Issued During Period, Value, Treasury Stock Reissued	4,156,000	3,939,000	'
Reissuance of treasury shares as a result of employee vesting	445,114	669,221	'
Retirement Plan	'	'	'
Stockholders Equity Note [Line Items]	'	'	'
Stock Issued During Period, Value, Treasury Stock Reissued	$4,200,000	$3,900,000	'

Noncontrolling_Interests_Addit

Noncontrolling Interests - Additional Information (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Noncontrolling Interest Note [Line Items]	'	'
Noncontrolling interests	$149,625	$147,396
Municipal bond fund	'	'
Noncontrolling Interest Note [Line Items]	'	'
Noncontrolling interests	122,300	126,300
Merchant banking fund	'	'
Noncontrolling Interest Note [Line Items]	'	'
Noncontrolling interests	19,300	14,100
Other private equity investments	'	'
Noncontrolling Interest Note [Line Items]	'	'
Noncontrolling interests	$8,000	$7,000

Noncontrolling_Interest_Rollfo

Noncontrolling Interest - Rollforward (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]	'	'
Stockholders' Equity Attributable to Parent	$734,676	'
Noncontrolling interest, beginning balance	147,396	'
Beginning Balance	882,072	'
Net income/(loss) applicable to Piper Jaffray Companies	17,748	10,146
Net income applicable to noncontrolling interests	5,138	1,901
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	22,886	12,047
Amortization/issuance of restricted stock	17,776	'
Stock Issued During Period, Value, Stock Options Exercised	273	'
Repurchase of common stock for employee tax withholding	-7,346	'
Issuance of treasury shares for 401k match	4,156	3,939
Shares reserved to meet deferred compensation obligations	120	'
Other comprehensive income	51	'
Fund Capital Contributions	-2,909	'
Stockholders' Equity Attributable to Parent	767,454	'
Noncontrolling interest, ending balance	149,625	'
Ending Balance	917,079	'
Parent	'	'
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]	'	'
Amortization/issuance of restricted stock	17,776	'
Stock Issued During Period, Value, Stock Options Exercised	273	'
Repurchase of common stock for employee tax withholding	-7,346	'
Issuance of treasury shares for 401k match	4,156	'
Shares reserved to meet deferred compensation obligations	120	'
Other comprehensive income	51	'
Fund Capital Contributions	0	'
Noncontrolling Interests	'	'
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]	'	'
Amortization/issuance of restricted stock	0	'
Stock Issued During Period, Value, Stock Options Exercised	0	'
Repurchase of common stock for employee tax withholding	0	'
Issuance of treasury shares for 401k match	0	'
Shares reserved to meet deferred compensation obligations	0	'
Other comprehensive income	0	'
Fund Capital Contributions	($2,909)	'

Compensation_Plans_Additional_

Compensation Plans - Additional Information (Detail) (USD $)

3 Months Ended

0 Months Ended

3 Months Ended

12 Months Ended

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

15-May-12

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2010

Mar. 31, 2014

plan

Minimum

Maximum

Maximum

Annual grants

Restricted Stock Units

Restricted Stock Units

Restricted Stock Units

Restricted Stock Units

Restricted Stock

Stock Options

Amended And Restated 2003 Annual And Long -Term Incentive Plan

Amended And Restated 2003 Annual And Long -Term Incentive Plan

2010 Employment Inducement Award Plan

Deferred Compensation Plans [Member]

New Employees [Member]

New Employees [Member]

Maximum

Maximum

Maximum

Award Earned Based on Shareholder Return Relative to Predetermined Peer Group

Award Earned Based on Total Shareholder Return

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of stock-based compensation plans

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity award grants authorized

'

'

'

'

'

'

'

'

'

'

'

'

'

7,000,000

'

'

Shares available for future issuance

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000

'

'

'

Award vesting period in years

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'5 years

'

Annual grant expense period

'

'

'

'

'

'1 year

'

'

'

'

'

'

'

'

'

'

Forfeitures recorded as a result of violating the post-termination restrictions

$0

$300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Restricted stock units, performance period

'

'

'

'

'

'

'36 months

'

'

'

'

'

'

'

'

'

Weighted average period over which restricted stock expense expected to be recognized

'

'

'

'

'

'

'3 years

'

'

'

'2 years 0 months 266 days

'

'

'

'

'

Award earning percentage

'

'

'

'

'

'

'

'

50.00%

50.00%

'

'

'

'

'

'

Number of years risk free interest rate

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

Term of stock options

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

'

'

'

Restricted shares granted to ARI employees, value

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7,000,000

'

Restricted shares granted, share

'

'

'

'

'

'

'

0

'

'

402,074

'

'

'

158,801

'

Compensation expense related to employee restricted stock awards

5,300,000

600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Tax benefit related to compensation costs for stock-based compensation arrangements

2,000,000

200,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unrecognized compensation cost related to restricted stock

'

'

'

'

'

'

'

'

'

'

11,800,000

0

'

'

'

'

Mutual funds

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

5,800,000

Deferred liabilities

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$5,800,000

Acquisition related compensation awards vesting period

'3 years

'

'2 years

'

'5 years

'

'

'

'

'

'

'

'

'

'

'

Compensation_Plans_Summary_of_

Compensation Plans - Summary of Outstanding Equity Awards (Details)	Mar. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Restricted stock outstanding	1,280,029	'
Total restricted stock outstanding	1,384,525	'
Stock options outstanding	359,072	469,289
ARI [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Total restricted stock outstanding	104,496	'
Restricted Stock Units	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Leadership grants	290,536	'
Amended And Restated 2003 Annual And Long -Term Incentive Plan	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Restricted stock outstanding	1,250,870	'
Amended And Restated 2003 Annual And Long -Term Incentive Plan | Annual grants	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Restricted stock outstanding	825,343	'
Amended And Restated 2003 Annual And Long -Term Incentive Plan | Sign-on grants	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Restricted stock outstanding	425,527	'
2010 Employment Inducement Award Plan	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Restricted stock outstanding	29,159	'

Compensation_Plans_RSU_Valuati

Compensation Plans - RSU Valuation Assumptions (Details) (Restricted Stock Units)	3 Months Ended
	Mar. 31, 2014
Grant Year 2013	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Risk-free Interest Rate	0.40%
Expected Stock Price Volatility	44.00%
Grant Year 2012	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Risk-free Interest Rate	0.38%
Expected Stock Price Volatility	47.60%

Compensation_Plans_Unvested_Re

Compensation Plans - Unvested Restricted Stock (Details) (Restricted Stock, USD $)	3 Months Ended
	Mar. 31, 2014
Restricted Stock	'
Unvested Restricted Stock or Stock Units	'
Beginning Balance	1,582,062
Granted	402,074
Vested	-599,611
Cancelled	0
Ending Balance	1,384,525
Weighted Average Grant Date Fair Value (in dollars per share)	'
Beginning Balance	$35.25
Granted	$40.12
Vested	$37.58
Cancelled	$0
Ending Balance	$35.66

Compensation_Plans_Unvested_Re1

Compensation Plans - Unvested Restricted Stock Units (Details) (Restricted Stock Units, USD $)	3 Months Ended
	Mar. 31, 2014
Restricted Stock Units	'
Unvested Restricted Stock or Stock Units	'
Beginning Balance	290,536
Granted	0
Vested	0
Cancelled	0
Ending Balance	290,536
Weighted Average Grant Date Fair Value (in dollars per share)	'
Beginning Balance	$15.83
Granted	$0
Vested	$0
Cancelled	$0
Ending Balance	$15.83

Compensation_Plans_Stock_Optio

Compensation Plans - Stock Options (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Options Outstanding	'	'	'
Beginning Balance	469,289	'	'
Granted	0	'	'
Exercised	-8,573	'	'
Cancelled	-55	'	'
Expired	-101,589	'	'
Ending Balance	359,072	'	'
Options exercisable at period end	359,072	'	'
Weighted Average Exercise Price (in dollars per share)	'	'	'
Beginning Balance	$44.83	'	'
Granted	$0	'	'
Exercised	$31.88	'	'
Cancelled	$39.62	'	'
Expired	$47.48	'	'
Ending Balance	$44.39	'	'
Options exercisable at period end	$44.39	'	'
Weighted Average Remaining Contractual Term (in Years)	'	'	'
Weighted Average Remaining Contractual Term (in Years)	'2 years 2 months	'2 years	'
Options exercisable at period end	'2 years 2 months	'	'
Aggregate Intrinsic Value	'	'	'
Aggregate Intrinsic Value of Stock Options	$1,757,075	'	$288,318
Options exercisable at end of period	$1,757,075	'	'

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]	'	'
Net income/(loss) from continuing operations	$17,748	$10,667
Net loss from discontinued operations	0	-521
Net income/(loss) applicable to Piper Jaffray Companies	17,748	10,146
Earnings allocated to participating securities	-1,659	-1,180
Net income applicable to Piper Jaffray Companies' common shareholders	$16,089	$8,966
Shares for basic and diluted calculations:	'	'
Average shares used in basic computation	14,612,000	15,582,000
Incremental common share attributable to share-based payment arrangements	45,000	28,000
Average shares used in diluted computation	14,657,000	15,610,000
Earnings/(loss) per basic common share	'	'
Income from continuing operations	$1.10	$0.60
Loss from discontinued operations	$0	($0.03)
Earnings per basic common share	$1.10	$0.58
Earnings/(loss) per diluted common share	'	'
Income from continuing operations	$1.10	$0.60
Loss from discontinued operations	$0	($0.03)
Earnings per diluted common share	$1.10	$0.57
Weighted average participating shares outstanding	1,510,839	2,055,679

Segment_Reporting_Reportable_S

Segment Reporting - Reportable Segment Financial Results (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]	'	'
Investment banking	$88,474	$40,821
Institutional sales and trading	44,034	40,147
Asset management	20,959	18,456
Investment income	6,768	5,065
Net revenues	168,133	109,533
Goodwill impairment	'	'
Operating expenses	135,420	91,365
Segment pre-tax operating income/(loss)	32,713	18,168
Pre-tax operating margin	19.50%	16.60%
Intangible asset amortization expense	2,318	1,661
Capital Markets	'	'
Segment Reporting Information [Line Items]	'	'
Investment banking	88,568	40,891
Institutional sales and trading	49,498	45,123
Asset management	1,737	1,019
Investment income	10,378	6,137
Interest Expense, Long-term Debt	1,740	1,949
Net revenues	148,441	91,221
Goodwill impairment	0	'
Segment pre-tax operating income/(loss)	27,511	12,763
Pre-tax operating margin	18.50%	14.00%
Intangible asset amortization expense	743	0
Asset Mgmt [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Management fees	19,136	17,086
Performance fees	86	351
Asset management	19,222	17,437
Investment income	470	875
Net revenues	19,692	18,312
Goodwill impairment	'	'
Operating expenses	14,490	12,907
Segment pre-tax operating income/(loss)	5,202	5,405
Pre-tax operating margin	26.40%	29.50%
Intangible asset amortization expense	1,575	1,661
Equities Financing [Member] | Capital Markets	'	'
Segment Reporting Information [Line Items]	'	'
Investment banking	35,301	14,303
Debt Financing [Member] | Capital Markets	'	'
Segment Reporting Information [Line Items]	'	'
Investment banking	13,539	17,032
Advisory Services | Capital Markets	'	'
Segment Reporting Information [Line Items]	'	'
Investment banking	39,728	9,556
Equity securities | Capital Markets	'	'
Segment Reporting Information [Line Items]	'	'
Institutional sales and trading	24,260	20,735
Debt securities | Capital Markets	'	'
Segment Reporting Information [Line Items]	'	'
Institutional sales and trading	25,238	24,388
Operating Expense [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Operating expenses	135,420	91,365
Operating Expense [Member] | Capital Markets	'	'
Segment Reporting Information [Line Items]	'	'
Operating expenses	$120,930	$78,458

Segment_Reporting_Net_Revenues

Segment Reporting - Net Revenues by Geographic Locations (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]	'	'
Net revenues	$168,133	$109,533
United States	'	'
Segment Reporting Information [Line Items]	'	'
Net revenues	165,325	105,726
Europe	'	'
Segment Reporting Information [Line Items]	'	'
Net revenues	$2,808	$3,807

Segment_Reporting_LongLived_As

Segment Reporting - Long-Lived Assets By Geographic Region (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Long-Lived Assets by Geographical Areas [Line Items]	'	'
Long Lived Assets	$291,666	$302,930
United States	'	'
Long-Lived Assets by Geographical Areas [Line Items]	'	'
Long Lived Assets	285,320	296,516
Europe	'	'
Long-Lived Assets by Geographical Areas [Line Items]	'	'
Long Lived Assets	$6,346	$6,414

Net_Capital_Requirements_and_O1

Net Capital Requirements and Other Regulatory Matters - Additional Information (Detail) (USD $)	Mar. 31, 2014
In Millions, unless otherwise specified
Schedule Of Compliance With Regulatory Capital Requirements For Broker Dealer [Line Items]	'
Net capital requirement	$1
Net capital requirement, percentage of aggregate debit balances arising from customer transactions	2.00%
Net capital requirement, percent of aggregate debit balances under restriction on business expansion or dividend payment	5.00%
Net capital	185.2
Amount of capital that exceeds the minimum net capital required	184.2
Committed Credit Facility [Member]	'
Schedule Of Compliance With Regulatory Capital Requirements For Broker Dealer [Line Items]	'
Revolving credit facility	250
Committed Credit Facility [Member] | Covenant Requirement	'
Schedule Of Compliance With Regulatory Capital Requirements For Broker Dealer [Line Items]	'
Minimum net capital required	$120