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	$ 68,979	$ 65,971	$ 131,098	$ 120,500
Adjustments to net income:
(Reversal of) provision for credit losses on loans and leases, excluding covered loans	10,000	(1,000)	10,000	(1,000)
Provision for losses on covered loans	1,091	(1,461)	1,588	3,194
Depreciation and amortization	9,508	7,885	24,490	15,713
Amortization of intangibles	1,226	1,454	2,603	2,941
Share-based employee compensation expense			11,246	10,636
Deferred income tax benefit			(7,905)	(3,492)
Gain on disposal of assets	(1,538)	(6,838)	(1,648)	(9,664)
Gain on sale of securities	(1,924)	(5,367)	(5,300)	(7,489)
Impairment loss on securities	271	248	336	248
Other, net			16,367	17,383
Net change in:
Trading securities			62,949	(3,802)
Other assets and other liabilities, net			(38,204)	(22,392)
Net cash provided by operating activities			207,620	122,776
Cash Flows From Investing Activities
Purchase of securities available-for-sale			(823,320)	(820,540)
Sales of securities available-for-sale	2,600	15,000	400,803	626,055
Maturities and paydowns of securities available-for-sale			1,366,066	1,133,677
Purchase of securities held-to-maturity			(148,849)	(537,894)
Maturities and paydowns of securities held-to-maturity			151,613	75,409
Loan originations, net of principal collections			(1,492,182)	(1,171,116)
Net payments for premises and equipment			(22,714)	(22,614)
Other investing activities, net			(140)	19,224
Net cash used in investing activities			(568,723)	(697,799)
Cash Flows From Financing Activities
Net increase in deposits			1,373,127	972,088
Net (decrease) increase in federal funds purchased			(320,000)	50,000
Issuance of long-term debt			29,609	18,070
Repayment of long-term debt			(24,126)	(19,765)
Proceeds from exercise of stock options			28,996	16,387
Tax benefit from exercise of stock options			5,521	3,240
Cash dividends paid			(47,042)	(44,374)
Other financing activities, net			(3,546)	(16,252)
Net cash provided by financing activities			1,042,539	979,394
Net increase in cash and cash equivalents			681,436	404,371
Cash and cash equivalents at beginning of year			656,451	935,946
Cash and cash equivalents at end of period	$ 1,337,887	$ 1,340,317	1,337,887	1,340,317
Cash paid during the period for:
Interest			21,656	26,484
Income taxes			62,645	55,461
Non-cash investing activities:
Transfer of loans to other real estate owned			$ 3,915	$ 4,131