Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities
Net income	$ 210,981	$ 140,077
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	21,856	15,778
Gains on sales of loans	(9,772)	(26,537)
Proceeds from sales of loans	569,768	601,694
Loans originated for sale	(599,671)	(577,874)
Net gains on sale of investment securities	(3)	(168)
Net losses (gains) from sales/writedowns of other real estate and repossessed assets	473	(597)
Depreciation of premises and equipment	12,735	13,444
Amortization of intangible assets	4,290	4,564
Additions to loan servicing rights	(6,337)	(6,461)
Valuation change in loan servicing rights	(2,529)	8,242
Net amortization of premiums and discounts on investment securities	14,174	13,933
Share-based compensation expense	5,991	14,573
Deferred income tax expense	18,134	36,508
Change in deferred tax valuation allowance	(456)	60
Net increase in interest receivable and other assets	(34,702)	(148,180)
Net increase in interest payable and other liabilities	12,583	40,181
Net cash provided by operating activities	217,515	129,237
Debt securities – available-for-sale:
Proceeds from maturities, calls and principal reductions	223,049	227,854
Proceeds from sales and redemptions	4,215	17,085
Purchases	(1,069,703)	(1,041,744)
Investment securities – held-to-maturity:
Proceeds from maturities, calls and principal reductions	91,317	73,762
Purchases	(23,523)	(109,704)
Net increase in loans	(661,400)	(862,498)
Proceeds from sales of other real estate and repossessed assets	10,156	15,569
Purchases of premises and equipment, net of disposals	(9,144)	(11,616)
Proceeds from returns of investment in equity method investments	326	143
Net cash used in investing activities	(1,434,707)	(1,691,149)
Cash flows from financing activities
Net increase in interest- and noninterest-bearing demand deposits and savings accounts	1,153,767	828,517
Net increase in time deposits	648,282	103,606
Net (decrease) increase in collateralized customer deposits and other short-term borrowings	(367,765)	1,146,550
Proceeds from issuance of long-term borrowings	200,000	0
Repayment of long-term borrowings	(142,000)	(200,000)
Cash dividends paid	(64,554)	(58,504)
Proceeds from directors’ stock plans and exercise of stock options, net of shares withheld	3,016	3,353
Cash paid for payroll taxes upon conversion of share-based awards	(4,782)	(26,801)
Net cash provided by financing activities	1,425,964	1,796,721
Net increase in cash and cash equivalents	208,772	234,809
Cash and cash equivalents at beginning of period	455,991	474,402
Cash and cash equivalents at end of period	664,763	709,211
Supplemental disclosures of cash flow information:
Interest paid	93,150	51,505
Net income tax payments	4,599	9,922
Non-cash activities:
Loans transferred to other real estate and repossessed assets	8,785	8,972
Net transfer of loans held-for-sale to loans held- for-investment	(1,928)	(2,651)
Closed branch offices transferred to other assets	0	1,634
Business combinations:
Fair value of tangible assets acquired (noncash)	0	420
Goodwill, loans servicing rights and other identifiable intangible assets acquired	0	1,034
Liabilities assumed	$ 0	$ 1,454