Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating Activities
Net income	$ 88,180	$ 95,489
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses, net	7,760	7,596
Depreciation and amortization	27,995	27,088
Net amortization of securities	6,411	5,811
Securities gains, net	0	(300)
Gains on sales of loans, net	(13,301)	(7,853)
Deferred income tax provision	11,600	17,400
Proceeds from sales of loans held for sale	943,804	679,037
Purchases and originations of loans held for sale	(985,935)	(656,031)
Originations and sales of mortgage servicing rights, net	(13,321)	(8,883)
Increase in bank-owned life insurance	(3,598)	(3,526)
Net decrease in other assets	18,480	5,289
Net decrease in other liabilities	(1,151)	(11,087)
Other operating activities, net	6,325	9,552
Net cash provided by operating activities	93,249	159,582
Investing Activities
Proceeds from calls and maturities of securities held to maturity	95,467	67,352
Proceeds from calls and maturities of securities available for sale	345,156	274,764
Proceeds from sales of securities available for sale	0	56,815
Purchases of securities held to maturity	(68,715)	(63,986)
Purchases of securities available for sale	(375,866)	(497,549)
Proceeds from bank owned life insurance	655	0
Net decrease in federal funds sold and securities purchased under reverse repurchase agreements	1,885	3,240
Net increase in member bank stock	(12,585)	0
Net increase in loans	(247,772)	(354,281)
Purchases of premises and equipment	(9,934)	(8,555)
Proceeds from sales of premises and equipment	2,896	4,632
Proceeds from sales of other real estate	33,809	37,730
Purchases of software	(6,576)	0
Investments in tax credit and other partnerships	(315)	(5,118)
Distributions received for investments in tax credit and other partnerships	0	7,037
Purchase of insurance book of business	(2,787)	0
Net cash used in investing activities	(244,682)	(477,919)
Financing Activities
Net decrease in deposits	(285,954)	(346,677)
Net increase in federal funds purchased and securities sold under repurchase agreements	90,661	356,264
Net increase in short-term borrowings	298,888	248,624
Payments on long-term FHLB advances	(77)	(138)
Common stock dividends	(46,952)	(46,852)
Common stock issued-net, long-term incentive plans	(842)	(795)
Excess tax expense from stock-based compensation arrangements	(212)	(353)
Net cash provided by financing activities	55,512	210,073
Decrease in cash and cash equivalents	(95,921)	(108,264)
Cash and cash equivalents at beginning of period	315,973	345,761
Cash and cash equivalents at end of period	$ 220,052	$ 237,497