Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
OPERATING ACTIVITIES
Net income	$ 67,621	$ 52,072
Adjustments to reconcile net income to cash provided by operating activities:
Provision (credit) for loan and lease losses	8,231	4,843
Deferred tax expense (benefit)	6,693	(8,806)
Net change in current taxes	27,462	35,678
Depreciation	22,616	22,053
Net increase (decrease) in accrued interest payable	150	324
Net (increase) decrease in income earned not collected	(617)	(3,482)
Gain on acquisitions	(12,017)	(1,704)
Securities (gains) losses	24	(4,628)
Loss on termination of FDIC shared-loss agreements	45	0
Origination of loans held for sale	(134,932)	(144,895)
Proceeds from sale of loans held for sale	162,837	140,160
Gain on sale of loans held for sale	(3,456)	(2,487)
(Gain) loss on sale of portfolio loans	(164)	0
Net writedowns/losses on other real estate	1,717	2,599
(Gain) loss on sales of premises and equipment	(156)	0
Net accretion of premiums and discounts	(10,985)	(12,201)
Amortization of intangible assets	5,271	5,586
Reduction FDIC receivable for shared-loss agreements	2,591	4,076
Net increase (decrease) in FDIC payable for shared-loss agreements	1,005	1,790
Net change in other assets	(15,078)	(19,678)
Net change in other liabilities	8,741	3,857
Net cash provided by operating activities	137,599	75,157
INVESTING ACTIVITIES
Net change in loans outstanding	(105,100)	(131,923)
Purchases of investment securities available for sale	(871,698)	(1,139,933)
Proceeds from maturities of investment securities held to maturity	15	61
Proceeds from maturities of investment securities available for sale	787,182	396,211
Proceeds from sales of investment securities available for sale	14,162	987,260
Net change in overnight investments	(856,442)	(805,699)
Proceeds from sales of portfolio loans	32,294	0
Cash (paid to) received from the FDIC for shared-loss agreements	(2,760)	(9,871)
Net payment to the FDIC for termination of shared-loss agreements	(285)	0
Proceeds from sale of other real estate	8,845	8,202
Proceeds fro sales of premises and equipment	2,205	0
Additions to premises and equipment	(15,459)	(13,595)
Business acquisitions, net of cash acquired	25,646	14,745
Net cash (used) provided by investing activities	(981,395)	(694,542)
FINANCING ACTIVITIES
Net change in time deposits	(107,339)	(84,802)
Net change in demand and other interest-bearing deposits	827,009	460,086
Net change in short-term borrowings	87,100	92,841
Repayment of long-term obligations	(442)	(68)
Origination of long-term obligations	0	75,000
Net cash provided (used) by financing activities	806,328	543,057
Change in cash and due from banks	(37,468)	(76,328)
Cash and due from banks at beginning of period	539,741	534,086
Cash and due from banks at end of period	502,273	457,758
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Transfers of loans to other real estate	5,822	9,980
Dividends declared but not paid	$ 3,603	$ 3,603