Business Combinations - Assets and Liabilities Assumed (Details) - USD ($) $ in Thousands	May 01, 2019	Apr. 02, 2019	Jun. 30, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill recorded for First South Bancorp			$ 296,764	$ 236,347
First South Bancorp
Business Acquisition [Line Items]
Purchase price	$ 37,486
Cash and due from banks	4,633
Overnight investments	3,188
Investment securities	23,512
Loans	179,243
Premises and equipment	4,944
Other real estate owned	1,567
Income earned not collected	604
Intangible assets	2,268
Other assets	19,192
Total assets acquired	239,151
Deposits	207,556
Borrowings	5,155
Other liabilities	2,850
Total liabilities assumed	215,561
Fair value of net assets acquired	23,590
Goodwill recorded for First South Bancorp	$ 13,896
Biscayne Bancshares
Business Acquisition [Line Items]
Purchase price		$ 118,949
Cash and due from banks		78,010
Overnight investments		306
Investment securities		34,539
Loans		863,384
Premises and equipment		1,533
Other real estate owned		2,046
Income earned not collected		3,049
Intangible assets		4,745
Other assets		41,572
Total assets acquired		1,029,184
Deposits		786,512
Borrowings		157,415
Other liabilities		12,829
Total liabilities assumed		956,756
Fair value of net assets acquired		72,428
Goodwill recorded for First South Bancorp		$ 46,521