Long-Term Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Long-term Debt, Fiscal Year Maturity [Abstract]
2019	$ 10,000
2020	12,693
2021	14,732
2022	13,754
2023	125,500
Thereafter	143,188
Total long-term obligations	319,867	$ 870,240
Trust Preferred Securities	118,500	116,500
Junior Subordinated Debt [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	122,167	120,105
Junior Subordinated Debt [Member] \| Junior subordinated debenture at 3-month LIBOR plus 1.75 percent maturing June 30, 2036
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 88,145	90,207
Junior Subordinated Debt [Member] \| Junior subordinated debenture at 3-month LIBOR plus 1.75 percent maturing June 30, 2036 \| Libor 3 Month Rate [Member]
Debt Instrument [Line Items]
Description of variable rate basis	3-month LIBOR
Basis spread on variable rate	1.75%
Junior Subordinated Debt [Member] \| Junior subordinated debenture at 3-month LIBOR plus 2.25 percent maturing June 15, 2034
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 percent maturing June 15, 2034 \| Libor 3 Month Rate [Member]
Debt Instrument [Line Items]
Description of variable rate basis	3-month LIBOR
Basis spread on variable rate	2.25%
Junior Subordinated Debt [Member] \| Junior subordinated debenture at 3-month LIBOR plus 2.85 percent maturing April 7, 2034
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 percent maturing April 7, 2034 \| Libor 3 Month Rate [Member]
Debt Instrument [Line Items]
Description of variable rate basis	3-month LIBOR
Basis spread on variable rate	2.85%
Junior Subordinated Debt [Member] \| Junior subordinated debenture at 3-month LIBOR plus 2.00 percent maturing July 7, 2036
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 4,124	0
Junior Subordinated Debt [Member] \| Junior subordinated debenture at 3-month LIBOR plus 2.00 percent maturing July 7, 2036 \| Libor 3 Month Rate [Member]
Debt Instrument [Line Items]
Description of variable rate basis	3-month LIBOR
Basis spread on variable rate	2.00%
Junior Subordinated Debt [Member] \| Junior subordinated debentures at 7.00 percent maturing December 31, 2026 \| Libor 3 Month Rate [Member]
Debt Instrument [Line Items]
Debt interest rate	7.00%
Capital Lease Obligations [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 13,160	7,795
Federal Home Loan Bank Advances [Member] \| Notes payable to Federal Home Loan Bank of Atlanta with rates ranging from 1.64 percent to 3.06 percent and maturing through August 2023
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 165,205	745,221
Federal Home Loan Bank Advances [Member] \| Notes payable to Federal Home Loan Bank of Atlanta with rates ranging from 1.64 percent to 3.06 percent and maturing through August 2023 \| Minimum
Debt Instrument [Line Items]
Debt interest rate	1.64%
Federal Home Loan Bank Advances [Member] \| Notes payable to Federal Home Loan Bank of Atlanta with rates ranging from 1.64 percent to 3.06 percent and maturing through August 2023 \| Maximum
Debt Instrument [Line Items]
Debt interest rate	3.06%
Subordinated Debt [Member] \| Junior subordinated debentures at 7.00 percent maturing December 31, 2026
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 20,000	0
Unamortized Purchase Accounting Adjustments [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	(1,426)	(2,964)
Other Long Term Debt [Member]
Long-term Debt, Fiscal Year Maturity [Abstract]
Total long-term obligations	$ 761	$ 83

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