CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets
Cash and due from banks	$ 303,373	$ 360,375
Interest-bearing deposits in other banks	737,571	333,642
Investment securities, at fair value (amortized cost: $5,985,031 as of December 31, 2020 and $4,080,663 as of December 31, 2019)	6,071,415	4,075,644
Loans held for sale	11,579	904
Loans and leases	13,279,097	13,211,650
Less: allowance for credit losses	208,454	130,530
Net loans and leases	13,070,643	13,081,120
Premises and equipment, net	322,401	316,885
Other real estate owned and repossessed personal property		319
Accrued interest receivable	69,626	45,239
Bank-owned life insurance	466,537	453,873
Goodwill	995,492	995,492
Mortgage servicing rights	10,731	12,668
Other assets	603,463	490,573
Total assets	22,662,831	20,166,734
Deposits:
Interest-bearing	11,705,609	10,564,922
Noninterest-bearing	7,522,114	5,880,072
Total deposits	19,227,723	16,444,994
Short-term borrowings	0	400,000
Long-term borrowings	200,010	200,019
Retirement benefits payable	143,373	138,222
Other liabilities	347,621	343,241
Total liabilities	19,918,727	17,526,476
Commitments and contingent liabilities (Note 18)
Stockholders' equity
Common stock ($0.01 par value; authorized 300,000,000 shares; issued/outstanding: 140,191,133 / 129,912,272 as of December 31, 2020; issued/outstanding: 139,917,150 / 129,928,479 as of December 31, 2019)	1,402	1,399
Additional paid-in capital	2,514,014	2,503,677
Retained earnings	473,974	437,072
Accumulated other comprehensive income (loss), net	31,604	(31,749)
Treasury stock (10,278,861 shares as of December 31, 2020 and 9,988,671 shares as of December 31, 2019)	(276,890)	(270,141)
Total stockholders' equity	2,744,104	2,640,258
Total liabilities and stockholders' equity	$ 22,662,831	$ 20,166,734