Parent Company Financial Information - Income Statement (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Income Statements, Captions [Line Items]
Gain on sale of investment securities	$ 1,815	$ 1,517	$ 97
Interest expense	68,424	105,585	76,293
Legal and professional	16,406	12,195	9,742
Other	14,680	15,994	15,783
Income Tax Benefit	43,928	53,848	51,932
Net Income	132,217	142,943	152,276
Parent Company
Condensed Income Statements, Captions [Line Items]
Other interest and dividends	141,982	85,851	678
Gain on sale of investment securities	0	0	0
Total Income	141,982	85,851	678
Interest expense	11,915	11,916	11,916
Legal and professional	2,842	2,779	870
Directors compensation	500	491	614
Other	1,306	1,294	1,287
Total Expenses	16,563	16,480	14,687
Income (Loss) Before Income Tax (Benefit) and Equity in Undistributed Income of Subsidiaries	125,419	69,371	(14,009)
Income Tax Benefit	(607)	(3,176)	(2,892)
Income (Loss) Before Equity in Undistributed Income of Subsidiaries	126,026	72,547	(11,117)
Equity in Undistributed Income of Subsidiaries	6,191	70,396	163,393
Net Income	$ 132,217	$ 142,943	$ 152,276