Consolidated Statement of Cash Flows - Unaudited - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 429,736	$ 244,176
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	70,402	68,926
Amortization of premiums and accretion of discount, net	11,310	(18,901)
Stock compensation costs	16,025	14,280
Deferred income tax benefit	2,571	(111)
(Reversal of) provision for credit losses	(15,000)	176,313
Net gains on sales of loans	(3,272)	(1,082)
Gains on sales of AFS debt securities	(824)	(11,169)
Loans held-for-sale:
Originations and purchases	(8,703)	(21,791)
Proceeds from sales and paydowns/payoffs of loans originally classified as held-for-sale	10,353	18,386
Proceeds from distributions received from equity method investees	3,564	1,107
Net change in accrued interest receivable and other assets	(73,809)	(456,374)
Net change in accrued expenses and other liabilities	(44,113)	257,397
Other net operating activities	5,571	(241)
Total adjustments	(25,925)	26,740
Net cash provided by operating activities	403,811	270,916
CASH FLOWS FROM INVESTING ACTIVITIES
Investments in qualified affordable housing partnerships, tax credit and other investments	(92,780)	(68,884)
Interest-bearing deposits with banks	(20,534)	(335,497)
Resale agreements:
Proceeds from paydowns and maturities	506,353	350,000
Purchases	(1,345,537)	(500,000)
AFS debt securities:
Proceeds from sales	164,898	484,380
Proceeds from repayments, maturities and redemptions	877,123	848,633
Purchases	(4,015,212)	(1,834,087)
Loans held-for-investment:
Proceeds from sales of loans originally classified as held-for-investment	248,540	144,015
Purchases	(542,839)	(145,695)
Other changes in loans held-for-investment, net	(1,389,832)	(2,475,089)
Proceeds from distributions received from equity method investees	4,983	1,948
Other net investing activities	2,388	(337)
Net cash used in investing activities	(5,602,449)	(3,530,613)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase in deposits	7,708,661	3,355,168
Net (decrease) increase in short-term borrowings	(21,143)	225,834
FHLB advances:
Proceeds	0	10,100
Repayment	(405,000)	(100,099)
Repayment of repurchase agreements	0	(150,000)
Repurchase agreements’ extinguishment cost	0	(8,740)
Long-term debt and lease liabilities:
Proceeds from long-term debt	0	1,437,269
Repayment of long-term debt and lease liabilities	(613)	(9,320)
Common stock:
Repurchase of common stocks pursuant to the Stock Repurchase Program	0	(145,966)
Proceeds from issuance pursuant to various stock compensation plans and agreements	1,180	1,170
Stocks tendered for payment of withholding taxes	(15,254)	(7,625)
Cash dividends paid	(95,060)	(80,271)
Net cash provided by financing activities	7,172,771	4,527,520
Effect of exchange rate changes on cash and cash equivalents	5,701	4,530
NET INCREASE IN CASH AND CASH EQUIVALENTS	1,979,834	1,272,353
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	4,017,971	3,261,149
CASH AND CASH EQUIVALENTS, END OF PERIOD	5,997,805	4,533,502
Cash paid during the period for:
Interest	52,228	145,723
Income taxes, net	114,202	5,609
Noncash investing and financing activities:
Loans transferred from held-for-investment to held-for-sale	247,636	143,283
Loans transferred to other real estate owned (“OREO”) and other foreclosed assets	$ 13,025	$ 19,504