CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
OPERATING ACTIVITIES:
Net income	$ 42,501	$ 47,523
Adjustments to reconcile net income to net cash provided by operating activities:
Net (accretion) amortization on investment securities	732	(21)
Net accretion on loans and amortization of core deposit intangible and operating lease components	(2,383)	(1,833)
Unrealized (gains) losses on equity securities with readily determinable fair value	173	(448)
Depreciation of premises and equipment	5,041	4,572
Amortization of mortgage servicing rights	1,593	733
Impairment of mortgage servicing rights	100
Provision for on-balance sheet exposures	29,294	21,691
Provision for off-balance sheet exposures	180
Net gain on sale of mortgage loans held for sale	(13,504)	(3,478)
Origination of mortgage loans held for sale	(343,941)	(122,696)
Proceeds from sale of mortgage loans held for sale	336,641	121,262
Net gain on sale of consumer loans held for sale	(3,006)	(2,618)
Origination of consumer loans held for sale	(282,612)	(346,413)
Proceeds from sale of consumer loans held for sale	284,898	324,260
Net gain realized on sale of other real estate owned	(4)	(220)
Impairment of premises held for sale		132
Deferred compensation expense - Class A Common Stock	427	332
Stock-based awards expense - Class A Common Stock	250	618
Net gain on sale of bank premises and equipment	(353)
Increase in cash surrender value of bank owned life insurance	(784)	(759)
Net change in other assets and liabilities:
Accrued interest receivable	1,765	(774)
Accrued interest payable	(1,685)	491
Other assets	(4,465)	581
Other liabilities	(9,486)	(7,775)
Net cash provided by operating activities	41,372	35,160
INVESTING ACTIVITIES:
Purchases of available-for-sale debt securities	(138,894)
Proceeds from calls, maturities and paydowns of available-for-sale debt securities	131,323	101,051
Proceeds from calls, maturities and paydowns of held-to-maturity debt securities	6,628	1,315
Net change in outstanding warehouse lines of credit	(312,321)	(269,099)
Net change in other loans	(342,083)	(137,490)
Proceeds from redemption of Federal Home Loan Bank stock	14,202	2,102
Purchase of Federal Home Loan Bank stock	(9,000)	(2,277)
Proceeds from sales of other real estate owned	32	580
Proceeds from sale of bank premises and equipment	894
Net purchases of premises and equipment	(2,139)	(4,083)
Net cash used in investing activities	(651,358)	(307,901)
FINANCING ACTIVITIES:
Net change in deposits	1,232,077	257,729
Net change in securities sold under agreements to repurchase and other short-term borrowings	9,780	43,012
Net change in Federal Reserve Payment Protection Plan Lending Facility borrowings	169,209
Payments of Federal Home Loan Bank advances	(1,037,500)	(565,000)
Proceeds from Federal Home Loan Bank advances	425,000	670,000
Repurchase of Class A Common Stock	(2,852)	(379)
Net proceeds from Class A Common Stock purchased through employee stock purchase plan	291	235
Net proceeds from Class A Common Stock options exercised and PSUs awarded	256	(102)
Cash dividends paid	(11,383)	(10,449)
Net cash provided by financing activities	784,878	395,046
NET CHANGE IN CASH AND CASH EQUIVALENTS	174,892	122,305
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	385,303	351,474
CASH AND CASH EQUIVALENTS AT END OF PERIOD	560,195	473,779
Cash paid during the period for:
Interest	14,992	21,561
Income taxes	10,008	6,726
SUPPLEMENTAL NONCASH DISCLOSURES:
Transfers from loans to real estate acquired in settlement of loans	2,109	1,295
Transfers from loans held for investment to held for sale		124,202
Unfunded commitments in low-income-housing investments	10,000
Right-of-use assets recorded	2,151	$ 40,202
Allowance for credit losses recorded upon adoption of ASC 326	$ 7,241