Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Operating Activities
Net income per consolidated statements of income	$ 75,479	$ 76,643
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses, net	4,281	6,837
Depreciation and amortization	19,123	19,534
Net amortization of securities	3,918	5,086
Gains on sales of loans, net	(9,098)	(9,999)
Compensation expense, long-term incentive plan	2,281	1,864
Deferred income tax provision	(4,400)	4,000
Proceeds from sales of loans held for sale	497,187	525,611
Purchases and originations of loans held for sale	(586,444)	(534,903)
Originations of mortgage servicing rights	(6,075)	(7,719)
Earnings on bank-owned life insurance	(2,715)	(2,639)
Net change in other assets	(14,988)	7,087
Net change in other liabilities	(417)	(2,658)
Other operating activities, net	18,498	(11,342)
Net cash from operating activities	(3,370)	77,402
Investing Activities
Proceeds from maturities, prepayments and calls of securities held to maturity	85,007	71,817
Proceeds from maturities, prepayments and calls of securities available for sale	213,479	226,479
Purchases of securities available for sale	(9,303)	(4,159)
Net proceeds from bank-owned life insurance	2,013	1,586
Net change in federal funds sold and securities purchased under reverse repurchase agreements	(74,669)	615
Net change in member bank stock	(173)	27,114
Net change in loans	(266,949)	(28,727)
Purchases of premises and equipment	(8,372)	(6,224)
Proceeds from sales of premises and equipment	2,373	651
Proceeds from sales of other real estate	4,105	10,681
Purchases of software	(6,861)	(7,359)
Investments in tax credit and other partnerships	(3,426)	(17)
Purchase of insurance book of business	(81)	0
Net cash from investing activities	(62,857)	292,457
Financing Activities
Net change in deposits	202,218	494,923
Net change in federal funds purchased and securities sold under repurchase agreements	1,329	8,064
Net change in short-term borrowings	127	(780,816)
Payments on long-term FHLB advances	(34)	(33)
Payments under finance lease obligations	(1,035)	0
Common stock dividends	(30,020)	(31,347)
Repurchase and retirement of common stock	(49,901)	(7,877)
Shares withheld to pay taxes, long-term incentive plan	(1,605)	(1,422)
Net cash from financing activities	121,079	(318,508)
Net change in cash and cash equivalents	54,852	51,351
Cash and cash equivalents at beginning of period	349,561	335,768
Cash and cash equivalents at end of period	$ 404,413	$ 387,119