Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash Flows from Operating Activities:
Net income	$ 176,067	$ 162,013	$ 138,573
Adjustments to reconcile net income to net cash provided by/(used in) operating activities:
Depreciation and amortization	29,280	33,988	30,066
Amortization of loans and advances to financial advisors and other employees	64,735	64,930	57,147
Amortization of of discount on investment portfolios	5,847	8,321	16,153
Provision for loan losses and allowance for loans and advances to financial advisors and other employees	9,713	10,618	3,457
Amortization of intangible assets	12,366	12,131	4,896
Deferred income taxes	5,256	(26,389)	45,519
Excess tax benefits from stock-based compensation	(19,858)	(12,018)	(16,722)
Stock-based compensation	94,006	137,447	40,747
(Gains)/losses on investments	22	13,319	(45,434)
Gain on acquisition		(7,566)
Other net	(9,778)	(3,640)	(181)
Decrease/(increase) in operating assets, net of assets acquired:
Cash segregated for regulatory purposes and restricted cash	(45,343)	128,142	(125,536)
Receivables:
Brokerage clients	58,917	(42,627)	72,220
Brokers, dealers and clearing organizations	(263,391)	(30,634)	(23,588)
Securities purchased under agreements to resell	169,997	(66,380)	(83,240)
Loans originated as held for sale	26,280	70,053	(288,657)
Proceeds from mortgages held for sale	(1,132,671)	(1,275,647)	(1,603,074)
Financial instruments owned, including those pledged	1,112,318	1,372,552	1,517,458
Loans and advances to financial advisors and other employees	(79,216)	(71,857)	(63,948)
Other assets	(2,509)	79,662	8,476
Increase/(decrease) in operating liabilities, net of liabilities assumed:
Brokerage clients	2,554	23,433	49,623
Brokers, dealers and clearing organizations	(8,198)	3,976	(1,492)
Drafts	488	(15,723)	14,532
Financial instruments sold, but not yet purchased	106,051	85,127	56,652
Other liabilities and accrued expenses	(62,664)	48,988	(67,914)
Net cash provided by/(used in) operating activities	250,269	702,219	(264,267)
Cash Flows from Investing Activities:
Maturities, calls, sales, and principal paydowns of available-for-sale	698,895	435,827	530,120
Calls and principal paydowns of held-to-maturity securities	96,618	93,703	15,464
Sale or maturity of investments	60,428	90,265	105,077
Sale of aircraft		45,951
Sale of other real estate owned	131	373	221
Increase in bank loans, net	(668,354)	(249,018)	(180,115)
Payments for:
Purchase of available-for-sale securities	(416,851)	(1,314,290)	(945,343)
Purchase of held-to-maturity securities	(7,959)	(16,438)	(531,379)
Purchase of investments	(48,834)	(71,777)	(80,887)
Purchase of fixed assets	(26,632)	(32,278)	(18,837)
Acquisitions, net of cash acquired	(80,378)	(88,592)	(120,180)
Net cash used in investing activities	(392,936)	(1,106,274)	(1,225,859)
Cash Flows from Financing Activities:
Proceeds from short-term borrowings from banks	(55,700)	(249,000)	105,300
Proceeds from issuance of senior notes, net	295,638		316,380
Proceeds from issuance of non-recourse debt, net			58,992
Increase/(decrease) in securities sold under agreements to repurchase	(224,629)	123,463	60,170
Increase/(decrease) in bank deposits, net	126,758	881,794	1,274,395
Increase/(decrease) in securities loaned	(35,914)	20,948	(105,208)
Excess tax benefits from stock-based compensation	19,858	12,018	16,722
Issuance of common stock for stock option exercises	317	650	41
Repurchase of treasury stock		(13,670)	(11,380)
Reissuance of treasury stock			11,562
Repayment of non-recourse debt		(58,992)
Extinguishment of subordinated debt	(3,131)	(2,187)	(1,639)
Net cash provided by financing activities	123,197	715,024	1,725,335
Effect of exchange rate changes on cash	(7,308)	1,650	1,061
Increase/(decrease) in cash and cash equivalents	(26,778)	312,619	236,270
Cash and cash equivalents at beginning of period	716,560	403,941	167,671
Cash and cash equivalents at end of period	689,782	716,560	403,941
Supplemental disclosure of cash flow information:
Cash paid for interest	40,471	46,360	29,064
Cash paid for income taxes, net of refunds	107,009	5,803	4,630
Noncash investing and financing activities:
Stock units granted, net of forfeitures	190,003	228,230	145,563
Issuance of common stock for acquisitions	19,183	265,066	21,750
Stone and Youngberg contingent earn-out		$ 3,266