Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Operating Activities
Net income	$ 95,489	$ 89,021
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses, net	7,596	(9,568)
Depreciation and amortization	27,088	27,800
Net amortization of securities	5,811	5,390
Securities gains, net	(300)	(378)
Gains on sales of loans, net	(7,853)	(24,220)
Deferred income tax provision	17,400	14,145
Proceeds from sales of loans held for sale	679,037	1,156,310
Purchases and originations of loans held for sale	(656,031)	(1,021,237)
Originations and sales of mortgage servicing rights, net	(8,883)	(15,551)
Increase in bank-owned life insurance	(3,526)	(510)
Net decrease in other assets	5,289	38,854
Net decrease in other liabilities	(11,087)	(3,431)
Other operating activities, net	9,552	7,390
Net cash provided by operating activities	159,582	264,015
Investing Activities
Proceeds from calls and maturities of securities held to maturity	67,352	7,269
Proceeds from calls and maturities of securities available for sale	274,764	642,687
Proceeds from sales of securities available for sale	56,815	67,558
Purchases of securities held to maturity	(63,986)	(35,045)
Purchases of securities available for sale	(497,549)	(1,000,015)
Purchase of bank owned life insurance	0	(100,000)
Net decrease (increase) in federal funds sold and securities purchased under reverse repurchase agreements	3,240	(821)
Net (increase) decrease in loans	(354,281)	59,025
Purchases of premises and equipment	(8,555)	(12,862)
Proceeds from sales of premises and equipment	4,632	3,782
Proceeds from sales of other real estate	37,730	30,389
Investments in tax credit and other partnerships	(5,118)	(12,755)
Distributions received for investment in tax credit and other partnerships	7,037	0
Net cash received in business combination	0	89,037
Net cash used in investing activities	(477,919)	(261,751)
Financing Activities
Net (decrease) increase in deposits	(346,677)	150,463
Net increase in federal funds purchased and securities sold under repurchase agreements	356,264	53,636
Net increase (decrease) in short-term borrowings	248,624	(21,174)
Payments on long-term FHLB advances	(138)	(383)
Redemption of junior subordinated debt securities	0	(33,000)
Common stock dividends	(46,852)	(46,674)
Common stock issued-net, long-term incentive plans	(795)	(118)
Excess tax expense from stock-based compensation arrangements	(353)	(808)
Net cash provided by financing activities	210,073	101,942
(Decrease) Increase in cash and cash equivalents	(108,264)	104,206
Cash and cash equivalents at beginning of period	345,761	231,489
Cash and cash equivalents at end of period	$ 237,497	$ 335,695