Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) shares in Millions		1 Months Ended	12 Months Ended
	Jun. 19, 2015	Jun. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Summary Of Significant Accounting Policies [Line Items]
Percentage of preferred stock issued by each REIT - less than			20.00%
Cash reserve or deposits			$ 113,800,000	$ 59,900,000
Allowance for loan losses			114,419,000	106,178,000	$ 102,353,000
FDIC loss-share receivable			7,200,000	8,300,000
OREO and repossessed assets total			10,600,000	19,000,000
Foreclosed assets acquired in FDIC-assisted transactions			588,000	$ 5,000,000
Foreclosed residential real estate properties			1,600,000
Properties for which formal foreclosure proceedings are in process			$ 7,100,000
Anti-dilutive common stock options and warrants			4.0	4.7	6.2
Series A Preferred Stock
Summary Of Significant Accounting Policies [Line Items]
Stock issued, shares	4.6	4.6
Minimum
Summary Of Significant Accounting Policies [Line Items]
Premises and equipment, useful life			3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Premises and equipment, useful life			40 years
Commercial loans | Minimum
Summary Of Significant Accounting Policies [Line Items]
Number of days past due of loans to be full or partial charged-off			90 days
Commercial loans | Maximum
Summary Of Significant Accounting Policies [Line Items]
Number of days past due of loans to be full or partial charged-off			120 days
Residential loans and home equity loans
Summary Of Significant Accounting Policies [Line Items]
Number of days past due of loans to be full or partial charged-off			120 days
Automobile
Summary Of Significant Accounting Policies [Line Items]
Number of days past due of loans to be fully charged-off			120 days
Unsecured consumer loans
Summary Of Significant Accounting Policies [Line Items]
Number of days past due of loans to be fully charged-off			150 days
First United Bancorp, Inc. | Park Avenue Bank Acquisition
Summary Of Significant Accounting Policies [Line Items]
FDIC loss share coverage percentage up to first tranche			95.00%
First United Bancorp, Inc. | Liberty Pointe Bank Acquisition
Summary Of Significant Accounting Policies [Line Items]
FDIC loss share coverage percentage up to first tranche			80.00%
First United Bancorp, Inc. | The Bank Of Miami
Summary Of Significant Accounting Policies [Line Items]
FDIC loss share coverage percentage up to first tranche			80.00%
First United Bancorp, Inc. | Old Harbor Bank
Summary Of Significant Accounting Policies [Line Items]
FDIC loss share coverage percentage up to first tranche			70.00%
PCI Loans
Summary Of Significant Accounting Policies [Line Items]
Allowance for loan losses			$ 0	$ 0
Commercial and industrial
Summary Of Significant Accounting Policies [Line Items]
Allowance for loan losses			50,820,000	48,767,000	$ 43,676,000
Loans evaluated for impairment			250,000
Trust preferred securities
Summary Of Significant Accounting Policies [Line Items]
Impairment charge part of combined amortized cost of the securities			$ 0	$ 0	$ 0