Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net income	$ 175,648	$ 167,921	$ 96,951
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	13,076	12,656	11,012
Provision charge (benefit) for credit losses	8,388	(24,339)	29,719
Credit loss (benefit) charge for off-balance sheet credit exposure	(3,384)	1,515	1,814
Deferred tax expense (benefit)	2,220	12,413	(7,929)
Amortization of operating lease right-of-use assets	10,617	10,074	9,012
Income on Bank-owned life insurance	(5,988)	(7,930)	(6,491)
Net amortization of premiums and discounts on securities	12,673	15,841	10,058
Accretion of net deferred loan fees	(9,262)	(7,763)	(9,492)
Amortization of premiums on purchased loans, net	270	604	1,032
Originations of loans held for sale	(22,295)	(47,675)	(87,413)
Proceeds from sales of loans originated for sale	20,521	49,530	89,126
ESOP expense	4,140	4,318	2,401
Allocation of stock award shares	9,407	5,451	5,330
Allocation of stock options	198	200	189
Net gain on sale of loans	(1,515)	(1,855)	(1,713)
Net gain on securities transactions	(181)	(255)	(81)
Net gain on sale of premises and equipment	(22)	(42)	(947)
Net gain on sale of foreclosed assets	(8,541)	(461)	(821)
(Increase) decrease in accrued interest receivable	(9,913)	4,460	8,472
(Increase) decrease in other assets	(56,291)	10,264	(106,811)
Increase (decrease) in other liabilities	60,544	(48,113)	59,883
Net cash provided by operating activities	200,310	156,814	103,301
Cash flows from investing activities:
Net (increase) decrease in loans	(649,216)	253,221	(717,947)
Proceeds from sales of foreclosed assets	16,155	1,368	3,610
Proceeds from maturities, calls and paydowns of investment securities held to maturity	73,841	47,637	62,051
Purchases of investment securities held to maturity	(27,043)	(34,599)	(49,228)
Proceeds from sales of securities available for sale	0	9,442	13,905
Proceeds from maturities calls and paydowns of securities available for sale	278,779	393,173	350,335
Purchases of securities available for sale	(290,426)	(1,400,980)	(248,863)
Proceeds from redemption of Federal Home Loan Bank stock	162,987	30,870	115,630
Purchases of Federal Home Loan Bank stock	(197,251)	(5,671)	(106,605)
Cash received, net of cash consideration paid for acquisition	0	0	78,089
BOLI claim benefits received	970	7,964	6,527
Purchases of loans	(6,971)	(5,230)	0
Proceeds from sales of premises and equipment	22	42	947
Purchases of premises and equipment	(9,411)	(13,805)	(12,825)
Net cash used in investing activities	(647,564)	(716,568)	(504,374)
Cash flows from financing activities:
Net (decrease) increase in deposits	(670,988)	1,396,183	977,442
Increase in mortgage escrow deposits	1,265	142	7,494
Purchase of treasury stock	(46,530)	(20,711)	(21,161)
Purchase of employee restricted shares to fund statutory tax withholding	(1,021)	(961)	(969)
Cash dividends paid to stockholders	(72,023)	(71,478)	(65,823)
Shares issued to dividend reinvestment plan	0	0	451
Stock options exercised	0	887	0
Proceeds from long-term borrowings	3,982,100	913,685	2,429,999
Payments on long-term borrowings	(3,252,556)	(1,454,440)	(2,286,722)
Net decrease in short-term borrowings	(18,948)	(8,443)	(294,033)
Repayment of subordinated debentures	0	(15,000)	0
Net cash (used in) provided by financing activities	(78,701)	739,864	746,678
Net (decrease) increase in cash and cash equivalents	(525,955)	180,110	345,605
Cash and cash equivalents at beginning of period	685,163	418,053	145,748
Restricted cash at beginning of period	27,300	114,300	41,000
Total cash, cash equivalents and restricted cash at beginning of period	712,463	532,353	186,748
Cash and cash equivalents at end of period	186,438	685,163	418,053
Restricted cash at end of period	70	27,300	114,300
Total cash, cash equivalents and restricted cash at end of period	186,508	712,463	532,353
Cash paid during the period for:
Interest on deposits and borrowings	46,896	35,910	49,419
Income taxes	51,050	57,471	36,514
Non cash investing activities:
Transfer of loans receivable to foreclosed assets	1,208	434	2,516
Non-cash assets acquired at fair value:
Investment securities	0	0	255,242
Loans, net	0	0	1,752,529
Bank-owned life insurance	0	0	37,237
Goodwill and other intangible assets, net	0	0	32,404
Bank premises and equipment	0	0	16,620
Other assets	0	0	23,587
Total non-cash assets acquired at fair value	0	0	2,117,619
Liabilities assumed:
Deposits	0	0	1,757,777
Borrowings and subordinated debt	0	0	226,656
Other Liabilities	0	0	30,447
Total liabilities assumed	0	0	2,014,880
Common stock issued for acquisitions	$ 0	$ 0	$ 180,828