Borrowings (Long-Term Obligations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Debt Issuance Costs, Net	$ (2,629)	$ (3,459)
Long-term Debt, Fiscal Year Maturity [Abstract]
2022	82,735
2023	125,500
2024	5,771
2025	0
2026	2,649
Thereafter	977,723
Total long-term obligations	1,194,378	1,248,163
Trust Preferred Securities	128,100	128,500
Obligation guaranteed for trust subsidiaries	14,400
Subordinated Debt | Fixed-to-Floating subordinated notes at 3.375% maturing March 15, 2030
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 350,000	350,000
Debt interest rate	3.375%
Junior Subordinated Debt [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 132,500
Junior Subordinated Debt [Member] | Junior subordinated debenture at 3-month LIBOR plus 1.75% maturing June 30, 2036(1)
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 88,145	88,145
Junior Subordinated Debt [Member] | Junior subordinated debenture at 3-month LIBOR plus 1.75% maturing June 30, 2036(1) | Libor 3 Month Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Long-term Debt, Fiscal Year Maturity [Abstract]
Description of variable rate basis	3-month LIBOR
Junior Subordinated Debt [Member] | Junior subordinated debenture at 3-month LIBOR plus 2.25% maturing June 15, 2034(1)
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 19,588	19,588
Junior Subordinated Debt [Member] | Junior subordinated debenture at 3-month LIBOR plus 2.25% maturing June 15, 2034(1) | Libor 3 Month Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%
Long-term Debt, Fiscal Year Maturity [Abstract]
Description of variable rate basis	3-month LIBOR
Junior Subordinated Debt [Member] | Junior subordinated debenture at 3-month LIBOR plus 2.85% maturing April 7, 2034(1)
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 10,310	10,310
Junior Subordinated Debt [Member] | Junior subordinated debenture at 3-month LIBOR plus 2.85% maturing April 7, 2034(1) | Libor 3 Month Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.85%
Long-term Debt, Fiscal Year Maturity [Abstract]
Description of variable rate basis	3-month LIBOR
Junior Subordinated Debt [Member] | Junior subordinated debentures at 3-month LIBOR plus 2.80% maturing March 30, 2034(1)
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 14,433	14,433
Junior Subordinated Debt [Member] | Junior subordinated debentures at 3-month LIBOR plus 2.80% maturing March 30, 2034(1) | Libor 3 Month Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.80%
Long-term Debt, Fiscal Year Maturity [Abstract]
Description of variable rate basis	3-month LIBOR
Junior Subordinated Debt [Member] | Junior subordinated debentures at 7.00% maturing December 31, 2026(2)
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 0	20,000
Junior Subordinated Debt [Member] | Junior subordinated debentures at 7.00% maturing December 31, 2026(2) | Libor 3 Month Rate [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Debt interest rate	7.00%
Junior Subordinated Debt [Member] | Junior subordinated debentures at 6.50% maturing October 1, 2025(3)
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 0	7,500
Junior Subordinated Debt [Member] | Junior subordinated debentures at 6.50% maturing October 1, 2025(3) | Libor 3 Month Rate [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Debt interest rate	6.50%
Notes payable to FHLB of Atlanta | Notes payable to FHLBs of Atlanta and Chicago with rates ranging from 0.75% to 2.99% and maturing through March 2032
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 644,659	655,175
Notes payable to FHLB of Atlanta | Notes payable to FHLBs of Atlanta and Chicago with rates ranging from 0.75% to 2.99% and maturing through March 2032 | Minimum
Long-term Debt, Fiscal Year Maturity [Abstract]
Debt interest rate	0.75%
Notes payable to FHLB of Atlanta | Notes payable to FHLBs of Atlanta and Chicago with rates ranging from 0.75% to 2.99% and maturing through March 2032 | Maximum
Long-term Debt, Fiscal Year Maturity [Abstract]
Debt interest rate	2.99%
Unsecured Term Loan [Member] | Unsecured term loan at 1-month LIBOR plus 1.10% maturing September 5, 2022
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 67,825	82,125
Unsecured Term Loan [Member] | Unsecured term loan at 1-month LIBOR plus 1.10% maturing September 5, 2022 | Libor 1 Month Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.10%
Long-term Debt, Fiscal Year Maturity [Abstract]
Description of variable rate basis	1-month LIBOR
Capital Lease Obligations [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 4,311	6,308
Unamortized Purchase Accounting Adjustments [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	(2,283)	(1,999)
Other Long Term Debt [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 19	$ 37