Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Activities
Net income	$ 184,540	$ 153,134
Adjustments to reconcile net income to net cash provided by operating activities:
Credit loss expense	39,165	57
Net amortization of debt securities	10,830	11,687
Net accretion of purchase accounting adjustments and deferred loan fees and costs	(23,369)	(2,680)
Amortization of debt modification costs	0	4,630
Origination of loans held for sale	(1,393,224)	(671,038)
Proceeds from loans held for sale	1,400,697	633,085
Gain on sale of loans	(73,236)	(23,929)
Gain on sale of debt securities	(1,015)	(14,158)
Bank-owned life insurance income, net	(2,059)	(1,629)
Stock-based compensation, net of tax benefits	2,829	6,554
Depreciation and amortization of premises and equipment	15,124	13,713
Gain on sale and write-downs of other real estate owned, net	(64)	(288)
Amortization of core deposit intangibles	7,758	5,919
Amortization of investments in variable interest entities	8,244	6,767
Net increase in accrued interest receivable	(33,558)	(5,348)
Net increase in other assets	(22,729)	(367)
Net (decrease) increase in accrued interest payable	(861)	61
Net decrease in other liabilities	(5,315)	(1,730)
Net cash provided by operating activities	113,757	114,440
Investing Activities
Sales of available-for-sale debt securities	0	711,268
Maturities, prepayments and calls of available-for-sale debt securities	545,191	457,299
Purchases of available-for-sale debt securities	(1,839,308)	(839,835)
Maturities, prepayments and calls of held-to-maturity debt securities	29,530	48,940
Principal collected on loans	2,978,796	2,497,073
Loan originations	(4,627,653)	(2,900,692)
Net additions to premises and equipment	(8,140)	(14,230)
Proceeds from sale of other real estate owned	2,140	2,960
Proceeds from redemption of non-marketable equity securities	76,275	115,436
Purchases of non-marketable equity securities	(71,397)	(93,397)
Investments in variable interest entities	(7,975)	(7,956)
Net cash received from acquisitions	43,713	79,334
Net cash (used in) provided by investing activities	(2,878,828)	56,200
Financing Activities
Net increase in deposits	2,920,429	377,986
Net increase in securities sold under agreements to repurchase	388,595	161,191
Net decrease in short-term Federal Home Loan Bank advances	(30,000)	(285,000)
Proceeds from long-term Federal Home Loan Bank advances	30,000	0
Repayments of long-term Federal Home Loan Bank advances	(31,271)	(151,073)
Net increase in other borrowed funds	463	97
Cash dividends paid	(73,999)	(70,970)
Tax withholding payments for stock-based compensation	(1,023)	(277)
Proceeds from stock option exercises	795	0
Net cash provided by financing activities	3,203,989	31,954
Net increase in cash, cash equivalents and restricted cash	438,918	202,594
Cash, cash equivalents and restricted cash at beginning of period	330,961	203,790
Cash, cash equivalents and restricted cash at end of period	769,879	406,384
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest	22,626	33,878
Cash paid during the period for income taxes	43,944	33,032
Supplemental Disclosure of Non-Cash Investing and Financing Activities
Sale and refinancing of other real estate owned	215	7
Transfer of loans to other real estate owned	2,062	2,347
Right-of-use assets obtained in exchange for operating lease liabilities	7,343	3,910
Dividends declared during the period but not paid	28,799	26,874
Acquisitions
Fair value of common stock shares issued	112,133	316,538
Cash consideration	13,721	16,424
Fair value of assets acquired	745,420	1,190,267
Liabilities assumed	$ 619,565	$ 1,024,141