Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net income	$ 32,697	$ 16,533
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of premises and equipment	2,064	2,126
Allocation of ESOP stock	352	347
Stock compensation	1,237	1,108
Net excess tax expense (benefit) on stock compensation	90	(299)
Amortization of servicing asset	25	12
Net premium amortization in excess of discount accretion on securities	1,467	842
Net amortization of deferred costs on borrowings	212	63
Amortization of core deposit intangible	1,395	1,578
Net accretion of purchase accounting adjustments	(3,804)	(5,637)
Net amortization of deferred costs and discounts on loans	437	40
(Benefit) provision for credit losses	(620)	9,969
Net gain on sale and write-down of other real estate owned	0	(2)
Net write down of fixed assets held-for-sale to net realizable value	427	0
Net gain on equity securities	(8,287)	(155)
Net gain on sales of loans	(1,916)	(173)
Proceeds from sales of residential loans held for sale	69,416	7,673
Mortgage loans originated for sale	(65,151)	(25,282)
Increase in value of bank owned life insurance	(1,415)	(1,575)
Net loss on sale of assets held for sale	22	0
Decrease (increase) in interest and dividends receivable	2,450	(2,095)
Deferred tax (benefit) provision	(57)	245
Decrease in other assets	27,442	10,877
(Decrease) increase in other liabilities	(21,610)	47,501
Total adjustments	4,176	47,163
Net cash provided by operating activities	36,873	63,696
Cash flows from investing activities:
Net increase in loans receivable	(111,302)	(160,211)
Proceeds from sale of loans	0	9,313
Purchase of debt securities available-for-sale	(100,921)	(9,980)
Purchase of debt securities held-to-maturity	(178,316)	0
Purchase of equity investments	(10,575)	(36)
Proceeds from sale of equity investments	99,060	0
Proceeds from maturities and calls of debt securities available-for-sale	22,850	10,223
Proceeds from maturities and calls of debt securities held-to-maturity	6,565	13,001
Proceeds from sales of debt securities available-for-sale	0	5,869
Principal repayments on debt securities available-for-sale	46	0
Proceeds from bank owned life insurance	2,120	155
Proceeds from the redemption of restricted equity investments	344	36,581
Purchases of restricted equity investments	(485)	(47,216)
Proceeds from sales of other real estate owned	0	89
Proceeds from sales of assets held-for-sale	420	0
Purchases of premises and equipment	(5,336)	(1,798)
Net cash consideration received for acquisition	0	23,460
Net cash used in investing activities	(223,159)	(85,149)
Cash flows from financing activities:
Increase (decrease) in deposits	75,694	(29,963)
Increase (decrease) in short-term borrowings	6,011	(50,297)
Proceeds from Federal Home Loan Bank advances	0	460,000
Repayments of Federal Home Loan Bank advances	0	(162,700)
Repayments of other borrowings	(7,529)	(27)
Increase in advances by borrowers for taxes and insurance	3,684	4,832
Exercise of stock options	1,762	657
Payment of employee taxes withheld from stock awards	(1,094)	(1,972)
Purchase of treasury stock	(9,994)	(14,814)
Dividends paid	(11,156)	(10,274)
Net cash provided by financing activities	57,378	195,442
Net (decrease) increase in cash and due from banks and restricted cash	(128,908)	173,989
Supplemental Disclosure of Cash Flow Information:
Cash and due from banks and restricted cash at beginning of period	1,318,661	133,226
Cash and due from banks at beginning of period	1,272,134	120,544
Restricted cash at beginning of period	46,527	12,682
Cash and due from banks at end of period	1,173,665	256,470
Restricted cash at end of period	16,088	50,745
Cash and due from banks and restricted cash at end of period	1,189,753	307,215
Cash paid during the period for:
Interest	10,376	19,293
Income taxes	568	0
Non-cash activities:
Accretion of unrealized loss on securities reclassified to held-to-maturity	180	199
Net loan (recoveries) charge-offs	(280)	1,154
Transfer of loans receivable to other real estate owned	0	106
Non-cash assets acquired:
Securities	0	208,880
Restricted equity investments	0	5,334
Loans	0	1,559,497
Premises and equipment	0	9,744
Accrued interest receivable	0	4,161
Bank owned life insurance	0	22,440
Deferred tax asset	0	(800)
Other assets	0	10,077
Goodwill and other intangible assets, net	0	139,275
Total non-cash assets acquired	0	1,958,608
Liabilities assumed:
Deposits	0	1,594,403
Borrowings	0	92,618
Other liabilities	0	33,602
Total liabilities assumed	0	1,720,623
Mortgage-backed Securities Held-to-Maturity
Cash flows from investing activities:
Principal repayments on debt securities held-to-maturity	$ 52,371	$ 35,401