Goodwill and Intangible Assets (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) $ / loans Rate	Dec. 31, 2019 USD ($) $ / loans Rate	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Goodwill [Roll Forward]
Beginning goodwill	$ 349,398	$ 236,347
Ending goodwill	350,298	349,398	$ 236,347
Servicing Asset at Amortized Cost	18,426	22,963	21,396	$ 21,945
Servicing Asset at Amortized Cost, Additions	8,006	6,149	5,258
Amortization	(8,400)	(6,233)	(5,807)
Valuation Allowance for Impairment of Recognized Servicing Assets, Provisions (Recoveries)	4,143	222	0
Residential Mortgage Loans Serviced	$ 3,310,000	$ 3,380,000	2,950,000
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Prepayment Speed | Rate	20.62%	13.72%
Contractually Specified Servicing Fee, Late Fee, and Ancillary Fee Earned in Exchange for Servicing Financial Asset	$ 8,500	$ 7,900	7,500
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Cost to Service Loans | $ / loans	87.58	87.09
Finite-lived Intangible Assets [Roll Forward]
Beginning balance	$ 43,386	$ 48,232
Amortization	(14,255)	(16,346)
Ending balance	29,667	43,386	48,232
Finite-Lived Intangible Assets [Abstract]
Gross balance	127,842	154,507
Accumulated amortization	(98,175)	(111,121)
Carrying value	29,667	43,386
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Finite-Lived Intangible Asset, Expected Amortization, Year One		10,948
Finite-Lived Intangible Asset, Expected Amortization, Year Two		7,743
Finite-Lived Intangible Asset, Expected Amortization, Year Three		5,129
Finite-Lived Intangible Asset, Expected Amortization, Year Four		2,658
Finite-Lived Intangible Asset, Expected Amortization, Year Five		3,189
Community Financial Holding Co. Inc.
Goodwill [Roll Forward]
Goodwill acquired	686
Finite-lived Intangible Assets [Roll Forward]
Intangible assets acquired	536
Biscayne Bancshares
Goodwill [Roll Forward]
Goodwill acquired		46,521
Finite-lived Intangible Assets [Roll Forward]
Intangible assets acquired		4,745
First South Bancorp
Goodwill [Roll Forward]
Goodwill acquired		13,896
Finite-lived Intangible Assets [Roll Forward]
Intangible assets acquired		2,268
Entegra Financial
Goodwill [Roll Forward]
Goodwill acquired	0	52,634
Business combination, measurement period adjustment, amount	214
Ending goodwill	52,600
Servicing Asset at Amortized Cost, Additions	$ 0	1,873	$ 0
Finite-lived Intangible Assets [Roll Forward]
Intangible assets acquired		$ 4,487
Conventional fixed loans
Goodwill [Roll Forward]
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Discount Rate | Rate	7.92%	8.92%
All loans and leases excluding conventional fixed loans [Member]
Goodwill [Roll Forward]
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Discount Rate | Rate	8.92%	9.92%
Core Deposit Intangibles
Goodwill [Roll Forward]
Useful life (years)	9 years