CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating Activities
Net income	$ 28,196	$ 113,655
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provision for loan losses	3,407	2,687
Depreciation, amortization and accretion, net	(11,830)	(14,486)
Net realized gains on securities	(46)	(4,403)
Bargain purchase gain		(81,289)
Deferred income taxes	494	(2,545)
Other, net	8,320	(3,814)
Net change in securities purchased under agreements to resell	9,014	(22,486)
Net change in assets segregated for regulatory purposes	37,899	(20,657)
Net change in trading securities	(154,279)	11,632
Net change in broker-dealer and clearing organization receivables	130,858	(793,613)
Net change in FDIC Indemnification Asset	11,214	23,376
Net change in other assets	(14,890)	(34,554)
Net change in broker-dealer and clearing organization payables	(162,722)	690,552
Net change in other liabilities	(48,283)	(52,528)
Net gains from sales of loans	(127,297)	(120,545)
Loans originated for sale	(3,052,579)	(2,904,331)
Proceeds from loans sold	3,352,409	3,094,705
Net cash provided by (used in) operating activities	9,885	(118,644)
Investing Activities
Proceeds from maturities and principal reductions of securities held to maturity	21,398	6,329
Proceeds from sales, maturities and principal reductions of securities available for sale	64,918	449,892
Purchases of securities available for sale	(51,531)	(2,623)
Net change in loans	(233,309)	(2,080)
Purchases of premises and equipment and other assets	(9,948)	(5,565)
Proceeds from sales of premises and equipment and other real estate owned	22,068	31,818
Net cash received for Federal Home Loan Bank and Federal Reserve Bank stock	12,311	4,044
Net cash from acquisitions		41,097
Net cash provided by (used in) investing activities	(174,093)	522,912
Financing Activities
Net change in deposits	139,925	(556,657)
Net change in short-term borrowings	(114,452)	72,540
Proceeds from notes payable	5,553	1,000
Payments on notes payable	(12,028)	(23,904)
Proceeds from issuance of common stock	3,850
Dividends paid on preferred stock		(1,426)
Net cash distributed to noncontrolling interest	(437)	(264)
Other, net	(139)	(99)
Net cash provided by (used in) financing activities	22,272	(508,810)
Net change in cash and cash equivalents	(141,936)	(104,542)
Cash and cash equivalents, beginning of period	669,445	813,075
Cash and cash equivalents, end of period	527,509	708,533
Supplemental Disclosures of Cash Flow Information
Cash paid for interest	16,377	14,325
Cash paid for income taxes, net of refunds	831	45,981
Supplemental Schedule of Non-Cash Activities
Conversion of loans to other real estate owned	4,726	$ 26,211
Common stock issued at acquisition		200,626
Additions to mortgage servicing rights	$ 1,639	$ 2,690