Consolidated Statements Of Cash Flows (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flows from Operating Activities:
Net income	$ 162,013,000		$ 84,134,000
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	33,988,000	30,066	28,267,000
Amortization of loans and advances to financial advisors and other employees	64,930,000	57,147	55,923,000
Amortization of premium on available-for-sale securities	8,321,000	16,153	12,782,000
Provision for loan losses and allowance for loans and advances to financial advisors and other employees	10,618,000	3,457	2,243,000
Amortization of intangible assets		4,896	5,311,000
Deferred income taxes	(26,389,000)	45,519	25,764,000
Excess tax benefits from stock-based compensation	(12,018,000)	(16,722)	(24,863,000)
Stock-based compensation	137,447,000	40,747	26,411,000
Gains on investments	13,319,000	(45,434)	1,877,000
Other net	(3,640,000)	(181)	841,000
Decrease/(increase) in operating assets:
Cash segregated for regulatory purposes and restricted cash	128,142,000	(125,536)	5,982,000
Receivables:
Brokerage clients	(42,627,000)	72,220	(82,210,000)
Brokers, dealers and clearing organizations	(30,634,000)	(23,588)	18,395,000
Securities purchased under agreements to resell	(66,380,000)	(83,240)	48,162,000
Loans originated as held for sale	(1,275,647,000)	(288,657)	(43,467,000)
Proceeds from mortgages held for sale	1,372,552,000	(1,603,074)	(1,060,457,000)
Trading securities owned, including those pledged	70,053,000	1,517,458	1,013,515,000
Loans and advances to financial advisors and other employees	(71,857,000)	(63,948)	(46,426,000)
Other assets	79,662,000	8,476	14,842,000
Increase/(decrease) in operating liabilities
Brokerage clients	23,433,000	49,623	33,244,000
Brokers, dealers and clearing organizations	3,976,000	(1,492)	(72,495,000)
Drafts	(15,723,000)	14,532	2,653,000
Trading securities sold, but not yet purchased	85,127,000	56,652	65,296,000
Other liabilities and accrued expenses	48,988,000	(67,914)	(70,310,000)
Net cash used in operating activities	702,219,000	(264,267)	45,414,000
Cash Flows from Investing Activities:
Maturities, calls, sales, and principal paydowns on available-for-sale securities	435,827,000	530,120	654,958,000
Calls on held-to-maturity securities	93,703,000	15,464	9,450,000
Sale or maturity of investments	90,265,000	105,077	76,263,000
Sale of other real estate owned	373,000	221	929,000
Increase in bank loans, net	(249,018,000)	(180,115)	(243,592,000)
Payments for:
Purchase of available-for-sale securities	(1,314,290,000)	(945,343)	(895,391,000)
Purchase of held-to-maturity securities	(16,438,000)	(531,379)	(119,960,000)
Purchase of investments	(71,777,000)	(80,887)	(119,720,000)
Purchase of fixed assets	(32,278,000)	(18,837)	(59,730,000)
Acquisitions	(88,592,000)	(120,180)	(18,817,000)
Net cash used in investing activities	(1,106,274,000)	(1,225,859)	(715,610,000)
Cash Flows from Financing Activities:
(Repayments of)/ proceeds from short-term borrowings from banks	(249,000,000)	105,300	89,800,000
Proceeds from Senior Note offering		316,380
Increase/(decrease) in securities sold under agreements to repurchase	123,463,000	60,170	(29,419,000)
Increase in bank deposits, net	881,794,000	1,274,395	448,170,000
Increase in securities loaned	20,948,000	(105,208)	97,537,000
Excess tax benefits from stock-based compensation	12,018,000	16,722	24,863,000
Issuance of common stock	650,000	11,603	3,983,000
Repurchase of common stock	(13,670,000)	(11,380)	(48,505,000)
Repayment of non-recourse debt	(58,992,000)
Extinguishment of subordinated debt	(2,187,000)	(1,639)	(1,284,000)
Net cash provided by financing activities	715,024,000	1,725,335	585,145,000
Effect of exchange rate changes on cash	1,650,000	1,061	(807,000)
Decrease in cash and cash equivalents	312,619,000	236,270	(85,858,000)
Cash and cash equivalents at end of period	716,560,000
Supplemental disclosure of cash flow information:
Cash paid for income taxes, net of refunds	5,803,000	4,630	5,547,000
Cash paid for interest	46,360,000	29,064	25,209,000
Noncash investing and financing activities:
Units, net of forfeitures	205,520,000	145,563	138,203,000
Issuance of common stock for acquisitions	$ 3,266,000