Mergers and Acquisitions - Pro Forma Combined Condensed Consolidated Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Brand Mortgage Group, LLC
Business Acquisition [Line Items]
Interest income	$ 357
Interest expense	279
Net interest income	78
Noninterest income	4,043
Noninterest expense	4,398
Net income before taxes	(277)
Metropolitan Bancgroup, Inc.
Business Acquisition [Line Items]
Net interest income	455,513	$ 450,353
Noninterest income	153,850	176,699
Noninterest expense	452,699	422,700
Net income before taxes	$ 115,646	$ 105,729
Earnings per share - pro forma:
Basic (usd per share)	$ 1.97	$ 1.80
Diluted (usd per share)	$ 1.97	$ 1.80