Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating Activities
Net income per consolidated statements of income	$ 116,514	$ 112,896
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses, net	7,180	15,043
Depreciation and amortization	29,585	29,512
Net amortization of securities	5,699	7,197
Gains on sales of loans, net	(17,556)	(16,409)
Compensation expense, long-term incentive plan	3,553	3,022
Deferred income tax provision	(6,400)	5,612
Proceeds from sales of loans held for sale	943,309	836,971
Purchases and originations of loans held for sale	(1,078,222)	(823,134)
Originations of mortgage servicing rights	(11,431)	(12,248)
Earnings on bank-owned life insurance	(4,239)	(3,994)
Net change in other assets	(31,241)	521
Net change in other liabilities	(1,625)	14
Other operating activities, net	26,874	(13,290)
Net cash from operating activities	(18,000)	141,713
Investing Activities
Proceeds from maturities, prepayments and calls of securities held to maturity	125,652	114,531
Proceeds from maturities, prepayments and calls of securities available for sale	306,630	334,852
Purchases of securities available for sale	(9,744)	(14,040)
Net proceeds from bank-owned life insurance	4,159	1,843
Net change in federal funds sold and securities purchased under reverse repurchase agreements	830	(385)
Net change in member bank stock	(285)	26,970
Net change in loans	(370,781)	(63,796)
Purchases of premises and equipment	(11,335)	(10,870)
Proceeds from sales of premises and equipment	2,374	651
Proceeds from sales of other real estate	6,698	16,490
Purchases of software	(9,541)	(10,701)
Investments in tax credit and other partnerships	(3,426)	(17)
Purchase of insurance book of business	(347)	0
Net cash from investing activities	40,884	395,528
Financing Activities
Net change in deposits	(110,228)	379,398
Net change in federal funds purchased and securities sold under repurchase agreements	326,241	17,038
Net change in short-term borrowings	344	(780,606)
Payments on long-term FHLB advances	(51)	(50)
Payments under finance lease obligations	(1,509)	0
Common stock dividends	(44,924)	(47,014)
Repurchase and retirement of common stock	(54,416)	(7,877)
Shares withheld to pay taxes, long-term incentive plan	(1,639)	(1,427)
Net cash from financing activities	113,818	(440,538)
Net change in cash and cash equivalents	136,702	96,703
Cash and cash equivalents at beginning of period	349,561	335,768
Cash and cash equivalents at end of period	$ 486,263	$ 432,471