Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities
Net income	$ 348,927	$ 298,528
Adjustments to reconcile net income to net cash provided by operating activities
Provision for credit losses	55,000	49,000
Depreciation and amortization of premises and equipment	27,429	27,141
Amortization of capitalized servicing rights	13,543	12,249
Amortization of core deposit and other intangible assets	8,420	12,319
Provision for deferred income taxes	36,731	50,075
Asset write-downs	5,118	8,940
Net gain on sales of assets	(11,647)	(5,399)
Net change in accrued interest receivable, payable	(23,782)	(16,530)
Net change in other accrued income and expense	(209)	70,766
Net change in loans originated for sale	712,954	211
Net change in trading account assets and liabilities	113,332	(59,080)
Net cash provided by operating activities	1,285,816	448,220
Cash flows from investing activities
Proceeds from sales of investment securities Available for sale		518
Proceeds from sales of investment securities Other	100	18,121
Proceeds from maturities of investment securities Available for sale	697,756	511,549
Proceeds from maturities of investment securities Held to maturity	121,455	132,636
Purchases of investment securities Available for sale	(5,143)	(311,302)
Purchases of investment securities Held to maturity	(539,516)	(5,343)
Purchases of investment securities Other	(278)	(124)
Net decrease (increase) in loans and leases	797,351	(439,712)
Net increase in interest-bearing deposits at banks	(1,944,511)	(1,950,831)
Capital expenditures, net	(21,521)	(16,307)
Net decrease in loan servicing advances	56,437	37,600
Other, net	11,863	7,920
Net cash used by investing activities	(826,007)	(2,015,275)
Cash flows from financing activities
Net increase in deposits	1,550,297	2,264,623
Net increase (decrease) in short-term borrowings	21,660	(343,838)
Payments on long-term borrowings	(1,401,410)	(317,187)
Purchases of treasury stock	(532,073)	(100,000)
Dividends paid - common	(116,566)	(112,000)
Dividends paid - preferred	(17,368)	(17,368)
Other, net	2,064	2,960
Net cash provided (used) by financing activities	(493,396)	1,377,190
Net decrease in cash and cash equivalents	(33,587)	(189,865)
Cash and cash equivalents at beginning of period	1,320,549	1,368,040
Cash and cash equivalents at end of period	1,286,962	1,178,175
Supplemental disclosure of cash flow information
Interest received during the period	1,001,129	968,223
Interest paid during the period	116,183	146,568
Income taxes paid (refunded) during the period	29,272	(86,146)
Supplemental schedule of noncash investing and financing activities
Real estate acquired in settlement of loans	23,607	33,737
Securitization of residential mortgage loans allocated to Available-for-sale investment securities	3,684	8,452
Securitization of residential mortgage loans allocated to capitalized servicing rights	$ 36	$ 92