Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 127,213	$ 178,550
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	70,680	12,295
Depreciation and amortization of premises and equipment	21,653	20,984
Amortization of TCI	22,883	24,608
Net amortization of investment securities premiums	8,722	6,861
Investment securities gains, net	(3,053)	(4,733)
Gain on sales of mortgage loans held for sale	(42,208)	(13,822)
Proceeds from sales of mortgage loans held for sale	1,113,671	672,314
Originations of mortgage loans held for sale	(1,127,256)	(665,338)
Amortization of intangible assets	397	1,285
Amortization of issuance costs and discounts on long-term debt	836	632
Stock-based compensation	5,403	5,458
Other changes, net	(169,447)	(195,560)
Total adjustments	(97,719)	(135,016)
Net cash provided by operating activities	29,494	43,534
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales of AFS securities	215,150	697,634
Proceeds from principal repayments and maturities of HTM securities	67,268	62,320
Proceeds from principal repayments and maturities of securities AFS	282,832	169,380
Purchase of AFS securities	(728,937)	(838,634)
Sale (purchase) of FRB and FHLB stock	3,458	(15,274)
Net increase in loans	(2,203,974)	(529,974)
Net change in tax credit investments	(18,550)	(23,799)
Net cash paid for acquisition	0	(3,907)
Net change in tax credit investments	9,585	14,715
Net cash used in investing activities	(2,392,338)	(496,969)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in demand and savings deposits	3,669,990	627,958
Net (decrease) increase in time deposits	(333,852)	338,600
Net (decrease) increase in short-term borrowings	(271,514)	78,083
Additions to long-term debt	495,898	305,000
Repayments of long-term debt	(82,491)	(571,197)
Net proceeds from issuance of common stock	5,046	3,813
Dividends paid	(63,387)	(64,439)
Acquisition of treasury stock	(39,748)	(111,457)
Net cash provided by financing activities	3,379,942	606,361
Net Increase in Cash and Cash Equivalents	1,017,099	152,926
Cash and Cash Equivalents at Beginning of Period	517,791	445,687
Cash and Cash Equivalents at End of Period	1,534,890	598,613
Cash paid during the period for:
Interest	91,328	134,935
Income taxes	12,118	7,966
Supplemental schedule of certain noncash activities:
Transfer of HTM securities to AFS securities	$ 0	$ 158,898