CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities
Net income	$ 24,680	$ 26,307
Adjustments to reconcile net income to net cash provided by operating activities:
Provision (recovery) for loan losses	(1,807)	1,705
Depreciation, amortization and accretion, net	1,577	(1,031)
Net change in fair value of equity securities	572
Deferred income taxes	(534)	1,531
Other, net	2,590	1,990
Net change in securities purchased under agreements to resell	(58,441)	(23,798)
Net change in assets segregated for regulatory purposes	(11,592)	14,598
Net change in trading securities	(25,466)	(107,766)
Net change in broker-dealer and clearing organization receivables	(164,957)	(39,422)
Net change in FDIC indemnification asset		19,424
Net change in other assets	(2,949)	(8,702)
Net change in broker-dealer and clearing organization payables	217,443	110,694
Net change in other liabilities	(108,306)	(104,858)
Net change in securities sold, not yet purchased	22,730	(9,696)
Proceeds from sale of mortgage servicing rights asset		17,499
Net gains from sales of loans	(105,767)	(124,150)
Loans originated for sale	(3,021,516)	(2,939,349)
Proceeds from loans sold	3,405,633	3,514,340
Net cash provided by operating activities	173,890	349,316
Investing Activities
Proceeds from maturities and principal reductions of securities held to maturity	14,095	15,152
Proceeds from sales, maturities and principal reductions of securities available for sale	44,925	83,048
Proceeds from sales, maturities and principal reductions of equity securities	15
Purchases of securities held to maturity	(14,848)	(831)
Purchases of securities available for sale	(116,393)	(240,757)
Purchases of equity securities	(217)
Net change in loans	48,859	57,902
Purchases of premises and equipment and other assets	(4,271)	(4,951)
Proceeds from sales of premises and equipment and other real estate owned	4,487	11,438
Net cash received from Federal Home Loan Bank and Federal Reserve Bank stock	9,716	34,953
Net cash used in investing activities	(13,632)	(44,046)
Financing Activities
Net change in deposits	(19,231)	245,777
Net change in short-term borrowings	(142,099)	(663,512)
Proceeds from notes payable	69,808	72,382
Payments on notes payable	(75,799)	(65,573)
Payments to repurchase common stock	(1,706)	(7,205)
Dividends paid on common stock	(6,719)	(5,802)
Net cash distributed to noncontrolling interest	(501)	(575)
Taxes paid on employee stock awards netting activity	(689)	(838)
Other, net	(177)	(356)
Net cash used in financing activities	(177,113)	(425,702)
Net change in cash and cash equivalents	(16,855)	(120,432)
Cash and cash equivalents, beginning of period	487,382	690,764
Cash and cash equivalents, end of period	470,527	570,332
Supplemental Disclosures of Cash Flow Information
Cash paid for interest	28,294	14,407
Cash paid for income taxes, net of refunds	542	1,262
Supplemental Schedule of Non-Cash Activities
Conversion of loans to other real estate owned	2,496	1,945
Additions to mortgage servicing rights	$ 6,661	$ 1,224