Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Operating Activities
Net income per consolidated statements of income	$ 55,283	$ 48,506
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses, net	1,514	6,755
Depreciation and amortization	18,729	17,679
Net amortization of securities	5,375	4,273
Securities gains (losses), net	(1)	310
Gains on sales of loans, net	(8,550)	(8,071)
Deferred income tax provision (benefit)	4,200	(2,100)
Proceeds from sales of loans held for sale	565,150	598,752
Purchases and originations of loans held for sale	(588,773)	(646,487)
Originations of mortgage servicing rights	(7,497)	(7,211)
Earnings on bank-owned life insurance	(2,487)	(2,429)
Net change in other assets	22,130	(8,963)
Net change in other liabilities	(5,676)	(857)
Other operating activities, net	2,588	16,933
Net cash provided by operating activities	61,985	17,090
Investing Activities
Proceeds from maturities, prepayments and calls of securities held to maturity	90,340	141,881
Proceeds from maturities, prepayments and calls of securities available for sale	230,945	213,709
Proceeds from sales of securities available for sale	26,409	24,693
Purchases of securities held to maturity	(69,989)	(121,931)
Purchases of securities available for sale	(292,170)	(240,482)
Net proceeds from bank-owned life insurance	0	604
Net change in federal funds sold and securities purchased under reverse repurchase agreements	500	(2,948)
Net change in member bank stock	474	(6)
Net change in loans	(374,640)	(272,617)
Purchases of premises and equipment	(8,142)	(5,135)
Proceeds from sales of premises and equipment	7,696	155
Proceeds from sales of other real estate	15,948	17,101
Purchases of software	(2,267)	(3,576)
Investments in tax credit and other partnerships	(2,893)	(46)
Net cash used in business acquisition	(19,775)	0
Net cash used in investing activities	(397,564)	(248,598)
Financing Activities
Net change in deposits	201,221	(56,706)
Net change in federal funds purchased and securities sold under repurchase agreements	(31,749)	165,294
Net change in short-term borrowings	192,799	(49,734)
Payments on long-term FHLB advances	(33)	(48)
Proceeds from long-term FHLB advances	0	250,000
Redemption of junior subordinated debt securities	(3,000)	0
Common stock dividends	(31,397)	(31,301)
Repurchase and retirement of common stock	0	(750)
Shares withheld to pay taxes, long-term incentive plan	(1,639)	(949)
Net cash provided by financing activities	326,202	275,806
Net change in cash and cash equivalents	(9,377)	44,298
Cash and cash equivalents at beginning of period	327,706	277,751
Cash and cash equivalents at end of period	$ 318,329	$ 322,049