Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CASH FLOWS FROM OPERATING ACTIVITIES:
NET INCOME	$ 165,114	$ 92,785	$ 190,559
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property	34,750	30,855	24,580
Amortization of deferred expenses, share-based incentive compensation and interest rate hedge	310,036	360,751	300,286
Amortization of intangible assets related to acquisitions	10,114	8,359	11,915
Deferred tax provision (benefit)	14,454	(4,457)	7,214
Loss (gain) on extinguishment of debt	50,757		(18,171)
(Increase) decrease in operating assets:
Deposits with banks	58,570	(806)	63,639
Cash deposited with clearing organizations and other segregated cash	4,811	11,613	16,408
Receivables-net	(30,126)	31,157	61,153
Investments	(61,502)	(30,096)	31,543
Other assets	(60,731)	(62,683)	(61,648)
Increase (decrease) in operating liabilities:
Deposits and other payables	(4,779)	(26,576)	(63,141)
Accrued compensation and benefits and other liabilities	35,229	71,006	(166,535)
Net cash provided by operating activities	526,697	481,908	397,802
CASH FLOWS FROM INVESTING ACTIVITIES:
Additions to property	(60,964)	(89,301)	(46,438)
Disposals of property	6,411	4,368	1,161
Net cash used in investing activities	(54,553)	(84,933)	(45,277)
Proceeds from:
Contribution from noncontrolling interests	832	1,741	17,505
Issuance of senior debt, net of expenses	493,398
Excess tax benefits from share-based incentive compensation	1,108		1,386
Payments for:
Senior and subordinated debt	(578,464)		(131,829)
Capital lease obligations	(2,659)	(2,519)	(2,322)
Distributions to noncontrolling interests	(14,367)	(27,767)	(33,734)
Repurchase of common membership interests from members of LAZ-MD Holdings			(794)
Purchase of Class A common stock	(132,477)	(354,464)	(204,835)
Class A common stock dividends	(121,620)	(135,108)	(70,572)
Settlement of vested share-based incentive compensation	(132,533)	(44,883)	(93,750)
Other financing activities	(290)	(220)	(33,414)
Net cash used in financing activities	(487,072)	(563,220)	(552,359)
EFFECT OF EXCHANGE RATE CHANGES ON CASH	6,220	12,644	(6,070)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(8,708)	(153,601)	(205,904)
CASH AND CASH EQUIVALENTS-January 1	850,190	1,003,791	1,209,695
CASH AND CASH EQUIVALENTS-December 31	841,482	850,190	1,003,791
Supplemental investing non-cash transaction:
Class A common stock issued/issuable in connection with business acquisitions			39,654
Cash paid during the year for:
Interest	78,671	78,441	92,702
Income taxes, net of refunds	$ 22,623	$ 23,267	$ 35,038