Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities:
Net income	$ 53,420,000	$ 32,004,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for Loan and Lease Losses	1,662,000	1,700,000
Specific reserve, other real estate owned	71,000	45,000
Depreciation of bank premises and equipment	6,273,000	6,227,000
Gain on sale of bank premises and equipment	(8,000)	(15,000)
Gain on sale of other real estate owned	(2,000)	(4,000)
Accretion of investment securities discounts	(75,000)	(120,000)
Amortization of investment securities premiums	5,700,000	7,021,000
Investment securities transactions, net		(927,000)
Unrealized loss on equity securities with readily determinable fair values	774,000
Amortization of identified intangible assets		25,000
Stock based compensation expense	185,000	268,000
Earnings from affiliates and other investments	(4,303,000)	(2,890,000)
Deferred tax expense	269,000	229,000
Increase in accrued interest receivable	1,683,000	2,047,000
(Increase) decrease in other assets	(42,473,000)	3,794,000
Net increase (decrease)in other liabilities	30,001,000	14,990,000
Net cash provided by operating activities	53,177,000	64,394,000
Investing activities:
Proceeds from maturities of securities	1,075,000
Proceeds from sales and calls of available for sale securities	18,145,000	121,549,000
Purchases of available for sale securities	(1,075,000)	(385,594,000)
Principal collected on mortgage backed securities	188,893,000	187,386,000
Net increase in loans	(107,206,000)	(46,999,000)
Purchases of other investments	(17,963,000)	(2,903,000)
Distributions from other investments	5,367,000	4,557,000
Purchases of bank premises and equipment	(3,519,000)	(3,962,000)
Proceeds from sales of bank premises and equipment	376,000	205,000
Proceeds from sales of other real estate owned	12,000	681,000
Net cash provided by (used in) investing activities	84,105,000	(125,080,000)
Financing activities:
Net increase in non-interest bearing demand deposits	196,102,000	197,317,000
Net increase in savings and interest bearing demand deposits	148,635,000	82,579,000
Net decrease in time deposits	(34,717,000)	(25,667,000)
Net decrease in securities sold under repurchase agreements	(94,852,000)	(195,208,000)
Net (decrease) increase in other borrowed funds	(363,625,000)	29,625,000
Purchase of treasury stock		(97,000)
Proceeds from stock transactions	440,000	744,000
Net cash (used in) provided by financing activities	(148,017,000)	89,293,000
(Decrease) increase in cash and cash equivalents	(10,735,000)	28,607,000
Cash and cash equivalents at beginning of period	265,357,000	269,198,000
Cash and cash equivalents at end of period	254,622,000	297,805,000
Supplemental cash flow information:
Interest paid	12,052,000	10,411,000
Non-cash investing and financing activities:
Net transfers from loans to other real estate owned	80,000	9,000
Dividends declared, not yet paid on common stock	$ 21,814,000	$ 21,793,000