Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income	$ (1,851,947)	$ 83,750	$ 111,810	$ 74,033
Adjustments to reconcile net income to net cash used in operating activities:
Goodwill impairment	1,784,936			0
Amortization of investment premiums, net	3,040			1,829
Loss on sale of investment securities, net	133			0
Provision for credit losses	118,085			13,684
Change in cash surrender value of bank owned life insurance	(2,163)			(2,135)
Depreciation, amortization and accretion	10,273			11,554
Loss (gain) on sale of premises and equipment	18			(195)
Gain on store divestiture	0			(1,225)
Additions to residential mortgage servicing rights carried at fair value	10,023			3,887
Change in fair value of residential mortgage servicing rights carried at fair value	30,687			13,966
Stock-based compensation	2,253			754
Net decrease (increase) in equity and other investments	182			(791)
Gain on equity securities, net	(814)			(695)
Gain on sale of loans and leases, net	(38,346)			(13,025)
Change in fair value of loans held for sale	(8,094)			(2,793)
Origination of loans held for sale	(1,148,184)			(487,090)
Proceeds from sales of loans held for sale	1,235,581			428,298
Change in other assets and liabilities:
Net increase in other assets	(219,221)			(57,027)
Net decrease in other liabilities	(25,117)			(28,872)
Net cash used in operating activities	(118,721)			(53,617)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of investment securities available for sale	(140,407)			(5,953)
Proceeds from investment securities available for sale	168,851			119,381
Proceeds from investment securities held to maturity	118			174
Purchases of restricted equity securities	(19,999)			(205,400)
Redemption of restricted equity securities	8,400			198,202
Net change in loans and leases	(109,523)			(23,252)
Proceeds from sales of loans and leases	22,038			15,848
Change in premises and equipment	(3,943)			(2,365)
Proceeds from bank owned life insurance death benefits	57			1,550
Net cash paid in store divestiture	0			(44,646)
Net cash (used in) provided by investing activities	(74,408)			53,539
CASH FLOWS FROM FINANCING ACTIVITIES:
Net increase in deposit liabilities	217,973			155,937
Net increase (decrease) in securities sold under agreements to repurchase	34,937			(8,207)
Proceeds from borrowings	600,000			230,670
Repayment of borrowings	(310,000)			(50,000)
Dividends paid on common stock	(46,248)			(46,254)
Proceeds from stock options exercised	0			21
Repurchase and retirement of common stock	(8,573)			(1,918)
Net cash provided by financing activities	488,089			280,249
Net increase in cash and cash equivalents	294,960			280,171
Cash and cash equivalents, beginning of period	1,362,756		$ 902,808	622,637
Cash and cash equivalents, end of period	1,657,716	$ 1,362,756		902,808
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest	53,213			44,026
Income taxes	38,732			34,383
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Changes in unrealized gains and losses on investment securities available for sale, net of taxes	80,143			24,712
Changes in unrealized gains and losses on junior subordinated debentures carried at fair value, net of taxes	58,579			4,920
Cumulative effect adjustment to retained earnings	40,181			244
Cash dividend declared on common stock and payable after period-end	46,237			46,297
Transfer of loans to loans held for sale	10,234			0
Change in GNMA mortgage loans recognized due to repurchase option	$ 992			$ (8,760)