Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 469,050	$ 309,471	$ 398,462
Adjustments to reconcile net income to net cash provided by operating activities:
Debt extinguishment cost	(353)	(2,530)	(44,422)
Provision for credit losses	82,848	33,797	(106,711)
Depreciation and amortization	123,086	85,878	57,691
Fixed income securities gains (losses), net	(102)	138,735	(10,419)
Deferred income tax expense (benefit)	(8,442)	(29,803)	25,938
Net decrease (increase) in trading securities	(66,635)	22,453	(36,045)
Net decrease (increase) in loans held for sale	972	(5,978)	38,610
Change in other liabilities	1,194	(5,759)	42,636
Change in other assets	(9,609)	(67,260)	(50,956)
Other, net	3,352	(19,712)	(23,287)
Net cash provided by operating activities	596,067	464,352	380,341
CASH FLOWS FROM INVESTING ACTIVITIES
Net decrease (increase) in money market investments	4,748,696	1,836,506	(105,066)
Proceeds from maturities and paydowns of investment securities held-to-maturity	93,306	123,178	108,404
Purchases of investment securities held-to-maturity	(415,654)	(61,036)	(164,704)
Proceeds from sales, maturities, and paydowns of investment securities available-for-sale	3,787,309	1,681,280	1,779,327
Purchases of investment securities available-for-sale	(9,358,633)	(5,513,366)	(1,794,525)
Net change in loans and leases	(2,101,518)	(562,827)	(1,005,171)
Purchases of premises and equipment	(195,663)	(157,361)	(175,799)
Proceeds from sales of other real estate owned	20,146	24,806	54,056
Other, net	14,243	(48,919)	(34,916)
Net cash used in investing activities	(3,436,254)	(2,579,901)	(1,268,562)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase in deposits	2,883,322	2,526,016	1,485,192
Net change in short-term funds borrowed	480,282	102,764	(96,125)
Repayments of long-term debt	(280,120)	(287,752)	(1,223,275)
Debt Extinguishment Costs Paid	(353)	(2,530)	(35,435)
Payments for Repurchase of Common Stock	(97,240)	(6,681)	(5,589)
Cash paid for preferred stock redemption	(126,144)	(175,669)	0
Proceeds from Issuances of common and preferred stock	25,072	22,392	526,438
Dividends paid on common and preferred stock	(107,851)	(108,055)	(96,130)
Other, net	2,227	1,441	2,030
Net cash provided by financing activities	2,779,195	2,071,926	557,106
Net decrease in cash and due from banks	(60,992)	(43,623)	(331,115)
Cash and due from banks at beginning of period	798,319	841,942	1,173,057
Cash and due from banks at end of period	737,327	798,319	841,942
Cash paid for interest	83,338	101,623	152,783
Net cash paid for income taxes	$ 214,300	$ 131,665	$ 182,954