CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating Activities
Net income	$ 59,071	$ 89,117
Adjustments to reconcile net income to net cash used in operating activities:
Provision (recovery) for loan losses	(1,467)	7,558
Depreciation, amortization and accretion, net	3,412	(14,436)
Net realized gains on securities		(14)
Net change in fair value of equity securities	512
Deferred income taxes	734	2,615
Other, net	4,926	5,264
Net change in securities purchased under agreements to resell	(42,635)	(35,758)
Net change in assets segregated for regulatory purposes	58,161	13,428
Net change in trading securities	96,488	(205,951)
Net change in broker-dealer and clearing organization receivables	(172,846)	(45,566)
Net change in FDIC indemnification asset		22,824
Net change in other assets	2,897	(48,794)
Net change in broker-dealer and clearing organization payables	52,574	75,004
Net change in other liabilities	(90,078)	(132,731)
Net change in securities sold, not yet purchased	18,760	(4,020)
Proceeds from sale of mortgage servicing rights asset	9,303	17,499
Net gains from sales of loans	(238,245)	(277,838)
Loans originated for sale	(7,308,972)	(7,151,419)
Proceeds from loans sold	7,286,188	7,221,859
Net cash used in operating activities	(261,217)	(461,359)
Investing Activities
Proceeds from maturities and principal reductions of securities held to maturity	24,047	27,975
Proceeds from sales, maturities and principal reductions of securities available for sale	90,950	197,327
Proceeds from sales, maturities and principal reductions of equity securities	3
Purchases of securities held to maturity	(21,634)	(36,299)
Purchases of securities available for sale	(170,328)	(361,530)
Purchases of equity securities	(492)
Net change in loans	(49,003)	(195,832)
Purchases of premises and equipment and other assets	(12,252)	(13,771)
Proceeds from sales of premises and equipment and other real estate owned	8,172	18,071
Net cash received from Federal Home Loan Bank and Federal Reserve Bank stock	(16,626)	8,165
Net cash used in investing activities	(147,163)	(355,894)
Financing Activities
Net change in deposits	(94,730)	483,993
Net change in short-term borrowings	404,311	97,780
Proceeds from notes payable	267,194	173,052
Payments on notes payable	(248,167)	(190,631)
Payments to repurchase common stock	(38,877)	(16,009)
Dividends paid on common stock	(13,453)	(11,603)
Net cash received from (distributed to) noncontrolling interest	644	(1,304)
Taxes paid on employee stock awards netting activity	(1,726)	(2,131)
Other, net	(363)	(332)
Net cash provided by financing activities	274,833	532,815
Net change in cash and cash equivalents	(133,547)	(284,438)
Cash and cash equivalents, beginning of period	487,382	690,764
Cash and cash equivalents, end of period	353,835	406,326
Supplemental Disclosures of Cash Flow Information
Cash paid for interest	65,349	36,299
Cash paid for income taxes, net of refunds	966	26,703
Supplemental Schedule of Non-Cash Activities
Conversion of loans to other real estate owned	4,846	5,644
Additions to mortgage servicing rights	$ 9,729	$ 2,490