CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Activities
Net income	$ 212,579	$ 112,558	$ 126,709
Adjustments to reconcile net income to net cash used in operating activities:
Provision for loan losses	12,715	16,933	37,158
Depreciation, amortization and accretion, net	(83,360)	(83,279)	(53,794)
Net realized gains on securities	(4,403)		(4,937)
Bargain purchase gain	(81,289)		(12,585)
Net gain on investment in SWS common stock		(5,985)
Deferred income taxes	17,376	(22,782)	15,829
Other, net	7,995	19,000	6,249
Net change in securities purchased under agreements to resell	(60,919)
Net change in assets segregated for regulatory purposes	99,010	(76,011)	18,998
Net change in trading securities	117,639	(6,871)	31,267
Net change in broker-dealer and clearing organization receivables	71,992	(145,283)	21,219
Net change in FDIC Indemnification Asset	39,936	61,299	(912)
Net change in other assets	(57,790)	(21,455)	(10,621)
Net change in broker-dealer and clearing organization payables	(54,048)	214,755	(55,247)
Net change in other liabilities	25,099	59,331	(35,260)
Net gains from sales of loans	(519,103)	(390,361)	(457,531)
Loans originated for sale	(13,871,473)	(10,839,905)	(11,752,800)
Proceeds from loans sold	14,163,781	11,016,636	12,522,963
Net cash provided by (used in) operating activities	35,737	(91,420)	396,705
Investing Activities
Proceeds from maturities and principal reductions of securities held to maturity	88,070	5,203
Proceeds from sales, maturities and principal reductions of securities available for sale	673,950	315,166	381,890
Purchases of securities held to maturity	(230,404)	(123,520)
Purchases of securities available for sale	(48,121)	(49,156)	(372,998)
Net change in loans	(150,605)	103,031	(140,437)
Purchases of premises and equipment and other assets	(31,270)	(43,186)	(33,066)
Proceeds from sales of premises and equipment and other real estate owned	110,922	69,400	21,233
Proceeds from redemption of bank owned life insurance	822
Net cash paid or Federal Home Loan Bank and Federal Reserve Bank stock	(12,172)	(17,114)	4,600
Net cash from acquisition	41,097		362,695
Net cash provided by investing activities	442,289	259,824	223,917
Financing Activities
Net change in deposits	(601,386)	(518,417)	(210,491)
Net change in short-term borrowings	20,437	420,609	(386,163)
Proceeds from notes payable	150,078	3,000	2,000
Payments on notes payable	(42,571)	(2,643)	(3,262)
Redemption of preferred stock	(114,068)
Payments to repurchase common stock	(30,028)
Dividends paid on preferred stock	(3,539)	(5,619)	(2,985)
Net cash distributed to noncontrolling interest	(1,222)	(902)	(2,640)
Other, net	643	2,620	2,482
Net cash used in financing activities	(621,656)	(101,352)	(601,059)
Net change in cash and cash equivalents	(143,630)	67,052	19,563
Cash and cash equivalents, beginning of period	813,075	746,023	726,460
Cash and cash equivalents, end of period	669,445	813,075	746,023
Supplemental Disclosures of Cash Flow Information
Cash paid for interest	59,700	28,846	31,805
Cash paid for income taxes, net of refunds	112,459	26,859	73,802
Supplemental Schedule of Non-Cash Activities
Conversion of available for sale investment to SWS common stock		71,502
Redemption of senior exchangeable notes for common stock			83,950
Conversion of loans to other real estate owned	$ 57,838	$ 67,542	$ 25,639
Common stock issued at acquisition	200,626