Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities:
Net income	$ 329,680	$ 381,668
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	34,316	664
Depreciation and amortization	24,915	24,603
Amortization of discounts and premiums, net	(3,381)	(25,114)
Amortization of core deposit intangibles	208	1,994
Net gain on sales of securities	(28,915)	(413)
Net gain on sales of loans	(87,200)	(49,809)
Stock-based compensation	27,283	24,611
Deferred tax (benefit) expense	(12,324)	37,569
Changes in operating assets and liabilities:
Decrease in other assets	536,552	353,403
Increase (decrease) in other liabilities	181,400	(11,608)
Origination of loans held for sale	(1,623,848)	(3,579,435)
Proceeds from sales of loans originated for sale	1,936,162	3,237,704
Net cash provided by operating activities	1,314,848	395,837
Cash Flows from Investing Activities:
Proceeds from repayment of securities held to maturity	175,375	2,356,766
Proceeds from repayment of securities available for sale	336,429	50,010
Proceeds from sales of securities held to maturity	547,925
Proceeds from sales of securities available for sale	246,209	264,413
Purchases of securities held to maturity	(13,030)	(10,086)
Purchase of securities available for sale	(390,932)	(271,836)
Redemption of Federal Home Loan Bank stock	79,254	463,623
Purchase of Federal Home Loan Bank stock	(67,794)	(386,007)
Proceeds from sales of loans	2,260,687	1,354,796
Other changes in loans, net	(664,320)	(2,623,161)
Purchase of premises and equipment, net	(26,722)	(69,665)
Net cash provided by investing activities	2,483,081	1,128,853
Cash Flows from Financing Activities:
Net increase in deposits	5,294	712,841
Net decrease in short-term borrowed funds	(460,000)	(1,927,800)
(Repayments of) proceeds from long-term borrowed funds	(850,000)	181,000
Net proceeds from issuance of preferred stock	502,840
Cash dividends paid on common stock	(249,094)	(248,081)
Cash dividends paid on preferred stock	(16,414)
Payments relating to treasury shares received for restricted stock award tax payments	(10,978)	(8,542)
Net cash used in financing activities	(1,078,352)	(1,290,582)
Net increase in cash and cash equivalents	2,719,577	234,108
Cash and cash equivalents at beginning of period	557,850	537,674
Cash and cash equivalents at end of period	3,277,427	771,782
Supplemental information:
Cash paid for interest	330,182	283,418
Cash paid for income taxes	110,651	135,192
Non-cash investing and financing activities:
Transfers to other real estate owned from loans	9,558	18,691
Transfer of loans from held for investment to held for sale	1,881,532	1,339,679
Shares issued for restricted stock awards	11,028	$ 8,985
Securities transferred from held to maturity to available for sale	$ 3,040,305