Parent Company Balance Sheet (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets:
Other Assets		$ 551,289	$ 343,353
Derivative Asset		187,422	78,385
Total assets		13,204,301	11,395,165
Liabilities and stockholders’ equity
Subordinated debentures (less unamortized debt issuance costs of $304 and $399)		49,696	49,601
Derivative Liability		117,959	53,923
Other liabilities		327,386	236,552
Total liabilities		11,501,616	9,687,022
Stockholders’ equity		1,702,685	1,708,143	$ 1,073,490	$ 943,809
Liabilities and Equity		13,204,301	11,395,165
Parent Company [Member]
Assets:
Cash	[1]	100,604	135,688
Investments in subsidiaries	[2]	1,761,383	1,743,435
Prepaid income taxes		1,927	31,586
Other Assets		642	612
Derivative Asset	[1]		290
Total assets		1,864,556	1,911,611
Liabilities and stockholders’ equity
Dividends payable		15,164	15,126
Long-term Debt		32,773	74,906
Junior subordinated debentures (less unamortized debt issuance costs of $37 and $40)		62,851	62,848
Subordinated debentures (less unamortized debt issuance costs of $304 and $399)		49,696	49,601
Derivative Liability	[1]	569	0
Other liabilities		818	987
Total liabilities		161,871	203,468
Stockholders’ equity		1,702,685	1,708,143
Liabilities and Equity		1,864,556	1,911,611
Parent Company [Member] | Junior Subordinated Debt [Member]
Liabilities and stockholders’ equity
Unamortized Debt Issuance Expense		37	40
Long-term Debt [Member]
Liabilities and stockholders’ equity
Unamortized Debt Issuance Expense		40	94
Long-term Debt [Member] | Parent Company [Member]
Liabilities and stockholders’ equity
Unamortized Debt Issuance Expense		40	94
Subordinated Debt [Member]
Liabilities and stockholders’ equity
Unamortized Debt Issuance Expense		304	399
Subordinated Debt [Member] | Parent Company [Member]
Liabilities and stockholders’ equity
Unamortized Debt Issuance Expense		$ 304	$ 399

[1] Entire balance eliminates in consolidation.

[2] Majority of balance eliminates in consolidation