CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
OPERATING ACTIVITIES:
Net income	$ 29,516	$ 27,469
Adjustments to reconcile net income to net cash provided by operating activities:
Net amortization on investment securities	(8)	(106)
Net accretion on loans and amortization of core deposit intangible and operating lease components	(596)	(702)
Unrealized (gains) losses on equity securities with readily determinable fair value	(289)	182
Depreciation of premises and equipment	2,263	2,447
Amortization of mortgage servicing rights	322	362
Provision for loan and lease losses	17,231	17,255
Net gain on sale of mortgage loans held for sale	(1,260)	(777)
Origination of mortgage loans held for sale	(40,714)	(29,410)
Proceeds from sale of mortgage loans held for sale	39,632	31,452
Net gain on sale of consumer loans held for sale	(1,405)	(1,637)
Origination of consumer loans held for sale	(146,087)	(164,496)
Proceeds from sale of consumer loans held for sale	147,466	167,562
Net gain realized on sale of other real estate owned	(130)	(132)
Impairment of premises held for sale	66	104
Deferred compensation expense - Class A Common Stock	233	55
Stock-based awards expense - Class A Common Stock	244	152
Increase in cash surrender value of bank owned life insurance	(382)	(371)
Net change in other assets and liabilities:
Accrued interest receivable	(28)	310
Accrued interest payable	536	(59)
Other assets	(2,026)	(97)
Other liabilities	(297)	2,439
Net cash provided by operating activities	44,287	52,002
INVESTING ACTIVITIES:
Purchases of available-for-sale debt securities		(69,940)
Proceeds from calls, maturities and paydowns of available-for-sale debt securities	48,775	174,255
Proceeds from calls, maturities and paydowns of held-to-maturity debt securities	600	1,375
Net change in outstanding warehouse lines of credit	(90,092)	(8,387)
Net change in other loans	(63,922)	(37,155)
Proceeds from redemption of Federal Home Loan Bank stock	2,102
Proceeds from sales of other real estate owned	229	266
Net purchases of premises and equipment	(1,036)	(3,738)
Net cash (used in) provided by investing activities	(103,344)	56,676
FINANCING ACTIVITIES:
Net change in deposits	318,171	284,465
Net change in securities sold under agreements to repurchase and other short-term borrowings	(9,822)	(28,339)
Payments of Federal Home Loan Bank advances	(520,000)	(347,500)
Proceeds from Federal Home Loan Bank advances	270,000	50,000
Repurchase of Class A Common Stock	(379)
Net proceeds from Class A Common Stock purchased through employee stock purchase plan	121
Cash dividends paid	(4,996)	(4,533)
Net cash provided by (used in) financing activities	53,095	(45,907)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(5,962)	62,771
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	351,474	299,351
CASH AND CASH EQUIVALENTS AT END OF PERIOD	345,512	362,122
Cash paid during the period for:
Interest	9,798	6,227
Income taxes	387	365
SUPPLEMENTAL NONCASH DISCLOSURES:
Transfers from loans to real estate acquired in settlement of loans	155	179
Unfunded commitments in low-income-housing investments		$ 9,033
Right-of-use assets recorded upon adoption of ASU 2016-02	$ 40,104