Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income for the period	$ 13,960	$ 119,550	$ 105,985	$ 220,760
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	(1,760)	(47,637)	(2,043)	(49,259)
Depreciation and amortization	35,113	31,150	69,282	63,554
Fixed income securities losses (gains), net	138,436	(5,026)	138,675	(35,940)
Deferred income tax expense	(44,431)	(58,870)	(41,029)	19,408
Net increase in trading securities	(2,899)	(247)	(3,920)	(22,109)
Net decrease (increase) in loans held for sale	(23,568)	(38,030)	(20,051)	6,954
Change in other liabilities	(61,829)	19,279	(36,263)	(58,517)
Change in other assets	32,079	(16,686)	(33,169)	(13,460)
Other, net	(70)	9,910	(3,619)	12,273
Net cash provided by operating activities	85,031	13,393	173,848	143,664
CASH FLOWS FROM INVESTING ACTIVITIES
Net decrease (increase) in money market investments	(754,443)	1,672,416	(501,169)	1,591,565
Proceeds from maturities and paydowns of investment securities held-to-maturity	21,587	19,190	60,910	38,125
Purchases of investment securities held-to-maturity	(1,485)	(27,514)	(24,061)	(63,264)
Proceeds from sales, maturities, and paydowns of investment securities available-for-sale	751,373	194,973	980,267	1,042,261
Purchases of investment securities available-for-sale	(972,714)	(221,701)	(1,757,570)	(673,824)
Net change in loans and leases	(148,336)	446,118	(47,894)	612,533
Net purchases of premises and equipment	(33,835)	(35,815)	(67,368)	(112,731)
Proceeds from sales of other real estate owned	5,172	17,087	8,573	28,912
Other, net	25,974	1,380	29,325	6,997
Net cash provided by (used in) investing activities	(810,035)	1,173,898	(1,223,199)	1,245,508
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase (decrease) in deposits	813,764	(861,165)	1,089,049	(690,743)
Net change in short-term funds borrowed	23,527	(21,436)	(17,099)	(81,947)
Repayments of long-term debt	(44,420)	(236,404)	(52,605)	(361,159)
Proceeds from issuances of common stock	5,070	1,641	6,032	4,521
Dividends paid on common and preferred stock	(29,045)	(24,207)	(52,279)	(47,948)
Other, net	(6,512)	(3,388)	(7,451)	(3,691)
Net cash provided by (used in) financing activities	762,384	(1,144,959)	965,647	(1,180,967)
Net increase (decrease) in cash and due from banks	37,380	42,332	(83,704)	208,205
Cash and due from banks at beginning of period	720,858	1,338,930	841,942	1,173,057
Cash and due from banks at end of period	758,238	1,381,262	758,238	1,381,262
Cash paid for interest	28,938	40,820	51,057	81,669
Net cash paid for income taxes	$ 92,326	$ 122,737	$ 91,826	$ 122,656