Condensed Financial Information (parent company only) - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets
Cash and due from banks	$ 167,146	$ 192,896
Premises and equipment	105,655	111,062
Interest receivable	57,187	53,948
Goodwill	545,385	543,918	$ 543,918
Cash surrender value of life insurance	291,041	292,745
Other assets	140,167	146,066
TOTAL ASSETS	15,453,149	14,067,210
Liabilities:
Subordinated debentures and term loans	118,618	118,380
Interest payable	2,762	3,287
Other liabilities	170,989	141,756
Total Liabilities	13,540,578	12,191,565
Stockholders' equity	1,912,571	1,875,645	$ 1,786,437	$ 1,408,260
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	15,453,149	14,067,210
Parent
Assets
Cash and due from banks	127,501	59,848
Investment in subsidiaries	1,900,787	1,930,852
Premises and equipment	274	195
Interest receivable	2	2
Goodwill	448	448
Cash surrender value of life insurance	716	861
Other assets	10,281	12,211
TOTAL ASSETS	2,040,009	2,004,417
Liabilities:
Subordinated debentures and term loans	118,618	118,380
Interest payable	864	860
Other liabilities	7,956	9,532
Total Liabilities	127,438	128,772
Stockholders' equity	1,912,571	1,875,645
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 2,040,009	$ 2,004,417