Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating Activities:
Net income	$ 292,250	$ 261,580
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan and lease losses	31,800	32,000
Deferred tax expense	3,647	13,138
Depreciation and amortization	28,159	28,991
Amortization of premium/discount on earning assets and funding, net	36,667	38,905
Stock-based compensation	9,684	8,598
Gain on sale, net of write-down, on foreclosed and repossessed assets	(827)	(745)
Loss on sale, net of write-down, on premises and equipment	1,213	295
Increase in cash surrender value of life insurance policies	(10,942)	(10,921)
Gain from life insurance policies	(4,626)	(1,453)
Mortgage banking activities	(3,829)	(3,684)
Proceeds from sale of loans held for sale	129,700	147,105
Origination of loans held for sale	(146,746)	(141,699)
Net increase in right-of-use lease assets	(4,274)	0
Net (increase) decrease in derivative contract assets net of liabilities	(164,977)	130,250
Net increase in accrued interest receivable and other assets	(25,803)	(9,506)
Net (decrease) increase in accrued expenses and other liabilities	(39,033)	3,529
Net cash provided by operating activities	132,063	496,383
Investing Activities:
Purchases of available for sale investment securities	(351,091)	(760,575)
Proceeds from maturities and principal payments of available for sale investment securities	394,369	445,704
Purchases of held-to-maturity investment securities	(1,289,977)	(283,770)
Proceeds from maturities and principal payments of held-to-maturity investment securities	400,779	414,487
Net proceeds from Federal Home Loan Bank stock	32,302	17,826
Alternative investments (capital call) return of capital, net	(4,040)	231
Net increase in loans	(1,147,426)	(826,400)
Proceeds from loans not originated for sale	20,542	674
Proceeds from life insurance policies	9,193	4,271
Proceeds from the sale of foreclosed and repossessed assets	10,901	7,046
Additions to premises and equipment	(18,771)	(25,481)
Net cash used for investing activities (1)	(1,943,219)	(1,005,987)
Financing Activities:
Net increase in deposits	1,421,819	1,003,445
Proceeds from Federal Home Loan Bank advances	5,725,000	5,225,000
Repayments of Federal Home Loan Bank advances	(6,158,959)	(5,460,221)
Net decrease in securities sold under agreements to repurchase and other borrowings	628,818	(78,781)
Issuance of long-term debt	300,000	0
Debt issuance costs	(3,642)	0
Dividends paid to common shareholders	(103,971)	(85,002)
Dividends paid to preferred shareholders	(5,906)	(5,906)
Exercise of stock options	621	2,110
Common stock repurchase program	(13,003)	(12,158)
Common shares purchased related to stock compensation plan activity	(6,289)	(13,689)
Net cash (used for) provided by financing activities	1,784,488	574,798
Net decrease in cash and due from banks	(26,668)	65,194
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Beginning of Period	329,499	256,786
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents End of Period	302,831	321,980
Supplemental disclosure of cash flow information:
Interest paid	151,859	104,861
Income taxes paid	90,574	51,237
Noncash investing and financing activities:
Real Estate Owned, Transfer to Real Estate Owned	7,224	5,548
Transfer of loans from portfolio to loans-held-for-sale	15,968	482
Operating Lease, Right-of-Use Asset	161,730	0
Operating Lease, Liability	$ 180,832	$ 0