Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating Activities
Net income	$ 106,783	$ 101,524
Adjustments to reconcile net income to net cash provided by operating activities:
Credit loss expense	36,296	57
Net amortization of debt securities	6,831	8,707
Net amortization (accretion) of purchase accounting adjustments and deferred loan fees and costs	33,329	(2,187)
Amortization of debt modification costs	0	825
Origination of loans held for sale	(847,288)	(353,921)
Proceeds from loans held for sale	849,626	346,144
Gain on sale of loans	(37,720)	(13,560)
Gain on sale of debt securities	(991)	(347)
Bank-owned life insurance income, net	(1,356)	(1,021)
Stock-based compensation, net of tax benefits	1,994	1,850
Depreciation and amortization of premises and equipment	9,907	9,011
Gain on sale and write-downs of other real estate owned, net	(169)	(334)
Amortization of core deposit intangibles	5,146	3,559
Amortization of investments in variable interest entities	4,973	3,885
Net increase in accrued interest receivable	(19,529)	(3,213)
Net increase in other assets	(15,048)	(6,520)
Net (decrease) increase in accrued interest payable	(602)	749
Net increase (decrease) in other liabilities	4,992	(9,518)
Net cash provided by operating activities	137,174	85,690
Investing Activities
Sales of available-for-sale debt securities	0	415,093
Maturities, prepayments and calls of available-for-sale debt securities	341,724	247,854
Purchases of available-for-sale debt securities	(1,042,423)	(457,915)
Maturities, prepayments and calls of held-to-maturity debt securities	20,250	32,575
Principal collected on loans	1,835,968	1,364,270
Loan originations	(3,371,733)	(1,675,181)
Net additions to premises and equipment	(4,861)	(11,882)
Proceeds from sale of other real estate owned	1,523	2,440
Proceeds from redemption of non-marketable equity securities	75,049	76,948
Purchases of non-marketable equity securities	(71,398)	(71,198)
Investments in variable interest entities	(7,321)	(6,451)
Net cash received from acquisitions	43,713	11,307
Net cash used in investing activities	(2,179,509)	(72,140)
Financing Activities
Net increase in deposits	2,001,950	86,429
Net increase in securities sold under agreements to repurchase	304,154	97,091
Net decrease in short-term Federal Home Loan Bank advances	(30,000)	(120,000)
Proceeds from long-term Federal Home Loan Bank advances	30,000	0
Repayments of long-term Federal Home Loan Bank advances	(631)	(987)
Net increase in other borrowed funds	43	54
Cash dividends paid	(46,324)	(47,560)
Tax withholding payments for stock-based compensation	(1,003)	(1,158)
Proceeds from stock option exercises	795	0
Net cash provided by financing activities	2,258,984	13,869
Net increase in cash, cash equivalents and restricted cash	216,649	27,419
Cash, cash equivalents and restricted cash at beginning of period	330,961	203,790
Cash, cash equivalents and restricted cash at end of period	547,610	231,209
Supplemental Disclosure of Cash Flow Information
Cash paid during the period for interest	16,282	22,244
Cash paid during the period for income taxes	8,550	21,680
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	791	1,914
Right-of-use assets obtained in exchange for operating lease liabilities	5,253	3,862
Dividends declared during the period but not paid	27,785	23,482
Fair value of common stock shares issued	112,133	87,153
Cash consideration	13,721	4
Fair Value of Assets Acquired	744,109	379,155
Liabilities Assumed	$ 618,255	$ 291,998