CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets
Cash and due from banks	$ 278,994	$ 303,373
Interest-bearing deposits in other banks	983,816	737,571
Investment securities, at fair value (amortized cost: $6,708,431 as of March 31, 2021 and $5,985,031 as of December 31, 2020)	6,692,479	6,071,415
Loans held for sale	9,390	11,579
Total Loans and Leases	13,300,289	13,279,097
Less: allowance for credit losses	200,366	208,454
Net loans and leases	13,099,923	13,070,643
Premises and equipment, net	319,949	322,401
Accrued interest receivable	69,879	69,626
Bank-owned life insurance	468,927	466,537
Goodwill	995,492	995,492
Mortgage servicing rights	10,869	10,731
Other assets	567,878	603,463
Total assets	23,497,596	22,662,831
Deposits:
Interest-bearing	11,958,606	11,705,609
Noninterest-bearing	8,175,075	7,522,114
Total deposits	20,133,681	19,227,723
Long-term borrowings	200,010	200,010
Retirement benefits payable	143,736	143,373
Other liabilities	336,539	347,621
Total liabilities	20,813,966	19,918,727
Stockholders' equity
Common stock ($0.01 par value; authorized 300,000,000 shares; issued/outstanding: 140,455,180 / 129,749,890 as of March 31, 2021; issued/outstanding: 140,191,133 / 129,912,272 as of December 31, 2020)	1,405	1,402
Additional paid-in capital	2,517,048	2,514,014
Retained earnings	497,418	473,974
Accumulated other comprehensive (loss) income, net	(43,435)	31,604
Treasury stock (10,705,290 shares as of March 31, 2021 and 10,278,861 shares as of December 31, 2020)	(288,806)	(276,890)
Total stockholders' equity	2,683,630	2,744,104
Total liabilities and stockholders' equity	$ 23,497,596	$ 22,662,831