Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows From Operating Activities
Net income	$ 114,218	$ 100,808
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	16,178	11,399
Amortization of other intangible assets	8,442	9,245
Net premium amortization on investment securities	11,263	14,331
Amortization of and net gains on termination of FDIC indemnification asset		(458)
Stock-based compensation expense	4,684	5,070
Excess tax (benefit) expense on stock-based compensation	126
Provision for loan losses	2,013	2,716
Net securities (gains) losses	(7,547)	(4,609)
Recognition of deferred gain on sale leaseback transactions	(1,612)	(2,325)
Gain on sale of ONB Insurance Group, Inc.		(41,864)
Net gains on sales of loans and other assets	(5,082)	(6,019)
Increase in cash surrender value of company-owned life insurance	(6,288)	(6,281)
Residential real estate loans originated for sale	(336,238)	(447,191)
Proceeds from sale of residential real estate loans	403,128	416,208
(Increase) decrease in interest receivable	6,039	(1,283)
(Increase) decrease in other real estate owned	8,287	7,022
(Increase) decrease in other assets	8,498	22,153
Increase (decrease) in accrued expenses and other liabilities	(4,370)	(11,059)
Total adjustments	107,521	(32,945)
Net cash flows provided by (used in) operating activities	221,739	67,863
Cash Flows From Investing Activities
Cash portion of bank purchase price, net of cash acquired		(62,532)
Proceeds from sale of ONB Insurance Group, Inc.		91,771
Purchases of investment securities available-for-sale	(566,089)	(1,281,062)
Purchases of Federal Home Loan Bank/Federal Reserve Bank stock	(15,647)	(10,974)
Proceeds from maturities, prepayments, and calls of investment securities available-for-sale	337,766	1,043,014
Proceeds from sales of investment securities available-for-sale	284,315	157,819
Proceeds from maturities, prepayments, and calls of investment securities held-to-maturity	53,586	16,324
Proceeds from redemption of Federal Home Loan Bank/Federal Reserve Bank stock	9
Proceeds from sales of trading securities	127
Reimbursements under FDIC loss share agreements		10,000
Net principal collected from (loans made to) loan customers	(389,264)	(322,876)
Proceeds from settlements on company-owned life insurance	2,347	3,422
Proceeds from sale of premises and equipment and other assets	15,058	6,332
Purchases of premises and equipment and other assets	(17,675)	(117,899)
Net cash flows provided by (used in) investing activities	(295,467)	(466,661)
Cash Flows From Financing Activities
Deposits	(136,469)	393,135
Federal funds purchased and interbank borrowings	104,018	(165,970)
Securities sold under agreements to repurchase	(81,643)	(42,737)
Payments for maturities of Federal Home Loan Bank advances	(893,363)	(592,877)
Payments for maturities of other borrowings	(116)	(50)
Proceeds from Federal Home Loan Bank advances	1,130,000	900,000
Cash dividends paid on common stock	(52,841)	(49,962)
Common stock repurchased	(1,917)	(1,905)
Proceeds from exercise of stock options	2,604	90
Common stock issued	303	296
Net cash flows provided by (used in) financing activities	70,576	440,020
Net increase (decrease) in cash and cash equivalents	(3,152)	41,222
Cash and cash equivalents at beginning of period	255,519	219,818
Cash and cash equivalents at end of period	252,367	261,040
Supplemental cash flow information:
Total interest paid	43,205	33,394
Total taxes paid (net of refunds)	$ 2,958	$ 25,900