Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
OPERATING ACTIVITIES
Net income	$ 185,445	$ 160,067
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	25,462	20,810
Provision for loan losses	38,337	28,528
Gain on sale of investments	(12,937)	(53)
Net accretion of investment securities and assets	(35,272)	(41,423)
Net amortization (accretion) on borrowings	273	(471)
Stock-based compensation expense	9,316	8,448
(Gain) loss on sale of foreclosed assets held for sale	(16)	150
Gain on sale of mortgage loans held for sale	(14,196)	(9,675)
Loss (gain) on sale of loans	4,451	(10)
Gain on sale of Visa, Inc. class B common stock	(42,860)
Fair value write-down of closed branches	0	954
Deferred income taxes	10,933	7,316
Income from bank owned life insurance	(3,438)	(3,310)
Originations of mortgage loans held for sale	(499,178)	(424,751)
Proceeds from sale of mortgage loans held for sale	490,674	410,269
Changes in assets and liabilities:
Interest receivable	(679)	(7,798)
Lease right-of-use assets	(1,370)
Other assets	3,802	(24,695)
Accrued interest and other liabilities	10,881	23,821
Income taxes payable	18,722	3,956
Net cash provided by operating activities	188,350	152,133
INVESTING ACTIVITIES
Net originations of loans	(299,013)	(1,034,175)
Proceeds from sale of loans	104,587	24,977
Decrease (increase) in due from banks - time	395	(640)
Purchases of premises and equipment, net	(37,523)	(17,084)
Proceeds from sale of foreclosed assets held for sale	16,139	20,739
Proceeds from sale of available-for-sale securities	561,374	7,726
Proceeds from maturities of available-for-sale securities	405,090	197,464
Purchases of available-for-sale securities	(593,700)	(634,791)
Proceeds from maturities of held-to-maturity securities	29,179	46,515
Purchases of held-to-maturity securities	0	(1,172)
Purchases of bank owned life insurance	0	(4,000)
Proceeds from bank owned life insurance death benefits	1,310	616
Disposition of assets and liabilities held for sale	1,245	(58,295)
Purchase of Reliance Bancshares, Inc.	(37,017)	0
Net cash provided by (used in) investing activities	152,066	(1,452,120)
FINANCING ACTIVITIES
Net change in deposits	(156,010)	995,631
Proceeds from issuance of subordinated notes	0	326,355
Repayments of subordinated debentures	0	(94,915)
Dividends paid on preferred stock	(326)	0
Dividends paid on common stock	(45,722)	(41,766)
Net change in other borrowed funds	(404,455)	40,893
Net change in federal funds purchased and securities sold under agreements to repurchase	6,598	(13,231)
Net shares issued under stock compensation plans	(3,301)	1,756
Shares issued under employee stock purchase plan	1,312	1,026
Retirement of preferred stock	(42,000)	0
Net cash (used in) provided by financing activities	(643,904)	1,215,749
DECREASE IN CASH AND CASH EQUIVALENTS	(303,488)	(84,238)
CASH AND CASH EQUIVALENTS, BEGINNING OF PERIOD	833,458	598,042
CASH AND CASH EQUIVALENTS, END OF PERIOD	$ 529,970	$ 513,804